DevGuru HTML Tag: input


			TAG: input
			<input> Available in versions: 2.0, 3.2, 4.0 Browser compatibility: Explorer 4, 5 Netscape 4, 6 The <input> tag is used to create individual form controls (fields). Control is a technical term that refers to the various elements (buttons, check boxes, radio buttons, text areas) that can be used inside a form to gather information. The four tags that can be used to build a form are: button input select textarea The form is the heart of an e-commerce page and the input tag is the heart of a form. There are ten types of form controls that can be created using the input tag. Appropriately, you must use the type attribute to determine the specific type of the control (field). The types are: button checkbox file hidden image password radio reset submit text Any number of input tags can be placed anywhere between a pair of opening and closing form tags to create the desired appearance of the form. There is no closing tag. Core Attributes class dir id lang onclick ondblclick onkeydown onkeypress onkeyup onmousedown onmousemove onmouseout onmouseover onmouseup style title Attributes accept The accept attribute is used with the type="file" control to specify what kind of files (including the path) that can be attached to the form. It is a comma-delimited list. For example: *accept="images/.gif" accesskey The accesskey attribute allows you to designate a key on the keyboard that when pressed, along with the alt or meta key, will bring focus to the input form element. This attribute is poorly supported. align deprecated 4.0 The align attribute is used with a type="image" control to place the image with respect to any surrounding text. The permitted values are bottom, left. middle, right, and top. This attribute is deprecated effective with version 4.0. However, most browsers continue to recognize this attribute. You are now to use style sheets. alt The alt attribute displays an alternative text for browsers that cannot display an image. checked The checked attribute is a Boolean value that, if present, allows a checkbox or radio button to be preselected (and have a preselected value). disabled The disabled attribute is a Boolean value that, if present, prevents the form control (field) from functioning. In some browsers, the control (field) will appear to be greyed out. ismap The ismap attribute is a Boolean value that, when present, signifies that the image is being used as a mouse-clickable server-side image map. maxlength The maxlength attribute sets the maximum number of characters that can be entered into a one line text window. name The name attribute is a string of characters that is used to label a form control (field) with a name. The name must be unique to that document and cannot be reused. onblur The onblur attribute is an event that allows the execution of JavaScript code when an element loses focus (for example, the mouse was clicked onto another element or a tab navigation directed the cursor elsewhere). onchange The onchange attribute is an event that allows the execution of JavaScript code when the form control (field) has been changed and loses focus. onfocus The onfocus attribute is an event that allows the execution of JavaScript code when an element comes into focus (for example, the mouse was clicked onto the element or a tab navigation brought the cursor to the element). onselect The onselect attribute is an event that allows the execution of JavaScript code when the form control (field) gains focus. readonly The readonly attribute allows you to display a value in a form control (field) that cannot be changed by the user. size The size attribute sets the width of a one line text window by defining how many characters can fit in the window. src The src attribute is the URL address or directory/file (path/name) where an image file is being stored. tabindex The tabindex attribute specifies an integer that defines the rank in the tabbing order for the specified element when you use the keyboard to navigate (tab through) a page. This attribute is poorly supported. type The type attribute determines the specific control. Note that by using style sheets you can effect the appearance of the various types of controls. However, the exact appearance will be browser dependent. type="button" The type="button" control creates a rectangular button that can be clicked when you wish a desired action to occur. For example, you could use buttons to navigate through a recordset data source being displayed on a web page. (See the RDS objects in the ADO Quick Reference.) If you want to reset or submit the form, you should use the type="reset" and type="submit" controls. A value for the name attribute is required. You can use the value attribute to assign a text that will be displayed on the face of the button. The default color is gray, but that can be changed using style sheets (see example at bottom of page). The text displayed on the button will set the minimum size, but you can set a different size using style sheets or the size attribute. Code: <input type="button" name="btn1" value="click me"> Output: type="checkbox" The type="checkbox" control creates a small, square button that can be selected or unselected by the user with a click of the mouse. When the checkbox is selected, a check mark appears within the box. A value for the name attribute is required. You must use the value attribute to assign a value that is associated with the checkbox. You can also use the checked attribute to precheck the checkbox. When the checkbox has been selected, the value is saved as part of the form information that is passed to the appropriate file and/or database when the form is submitted. However, the value for any unselected checkbox is not saved or passed. Code: <input type="checkbox" name="ckbx1" value="true"> Output: type="file" The type="file" control is used to attach a file to a form. When the form is submitted, the file is passed along with all the other contents of the form. This control displays an input window and a browse button. By clicking on the browse button, the user can search your directories for the desired file. When you find it, a double mouse click will select the file. Alternately, you can enter the path and name of the file into the input window. A value for the name attribute is required. You do not use the value attribute. To use the type="file", you must set both the enctype and method attributes of the form tag exactly as shown in the following code snippet. Code: <form method="post" enctype="multipart/form-data" action="next.asp"> ... <input type="file" name="file1"> Output: type="hidden" The type="hidden" control is used to add content to the form that cannot be viewed or changed by the user. When the form is submitted, the hidden content is passed along with all the other contents of the form. The hidden content is essentialy a name/value pair. You must provide a name using the name attribute. You also must provide a value. This value can be any textual or numeric information. Code: <input type="hidden" name="SocSecNum" value="123-45-6789"> type="image" The type="image" control allows you to use a graphic image or a picture as the equivalent of a type="submit" button. For example, you could create your own submit gif. Indeed, the specified image will perform exactly as a submit button, when you click the image, the form is submitted. The type="image" also allows you to display a mouse-sensitive image map within a form. (This requires that the browser be able to capture and process the X/Y coordinates of the mouse.) You must use the src attribute to list the location of the image file. You can use the alt attribute to provide text for browsers that cannot display an image. Some browsers, by default, place a border around the image. Code: <input type="image" name="submitgif" src="images/submit.gif" onclick="submitform()" border="0"> Output: type="password" The type="password"** control displays a one line input window which is used to collect a password as a masked text. A masked text means that when the user types in the password, the actual characters being typed do not appear in the window. Rather an asterisk * is displayed in place of each character in the password. You can use a type="text" control to gather the user name. The default window size is browser dependent and is usually 20-30 characters in length. However, you can set the size using style sheets or the size attribute. The maxlength attribute can be used to set the maximum number of characters that will be accepted by the control (field). This is only a semi-secure method for gathering a password. While the password is not visible on screen, when the form is submitted, the password is passed unencrypted as part of the contents of the form. Code: <input type="password"> Output: type="radio" The type="radio" control is used to create a small round circular button with a white center that can be selected or unselected by the user with a click of the mouse. When the radio button is selected, a black dot appears in the center of the circle. The concept is to present the user with a selection of choices, but only to allow one choice to be made, for example, picking the color of a tee-shirt being ordered on a web site from a selection of twelve different colors. Each related group of radio buttons must have the same name. Further, each radio button in a related group must have a different value. When a specific radio button is selected, only the value for the selected button is passed as part of the contents of the form upon submission. The values for the unselected radio buttons are not passed. You cannot change the size or color of a radio button. You can use the checked attribute to preselect one of the radio buttons. Code: <input type="radio" name="radio1" value="one" checked> <input type="radio" name="radio1" value="two"> <input type="radio" name="radio1" value="three"> <input type="radio" name="radio1" value="four"> Output: type="reset" The type="reset" control creates a rectangular button that can be clicked when the user wants to clear all of the fields in a form. The form is redisplayed in its original presentation. By default the reset button is a gray color and has the text "Reset" displayed inside the button. However, you can change the color using style sheets and you can use the value button to provide a different text for the button. The text displayed on the button will set the minimum size, but you can set a different size using style sheets or the size attribute. A name is not required, but it is becoming a very common coding practice to give a unique name to every control (field) in a form. Code: <input type="reset" value="Clear The Form" name="reset1"> Output: type="submit" The type="submit" control creates a rectangular button that can be clicked when the user wants to submit the contents of a form for processing. A form can be submitted to the same page or to another URL. This is set inside the form tag by using the action attribute. However, if it is important that certain contents of the form be filled out correctly, then you could use the onclick core attribute in the submit button to direct the submission to a JavaScript function that proofs the contents. Alternatively, you could use an onsubmit attribute inside the form tag to direct the submission to the JavaScript function. This is called client-side form verification. By default the submit button is a gray color and has the text "Submit Query" displayed inside the button. However, you can change the color using style sheets and you can use the value button to provide a different text for the button. The text displayed on the button will determine the minimum size, but you can set a different size using style sheets or the size attribute. A name is not required, but it is becoming a very common coding practice to give a unique name to every control in a form. If you assign a value, when the form is submitted, that value will be passed as part of the contents. Code: <input type="submit" name="submit" onclick="submitform()" value="Submit"> Output: type="text" The type="text" control displays a one line text input window into which the user can type the requested information (such as an address or phone number). If the requested information will require more than one line to enter, you should use a textarea tag rather than a type="text" control. The default window size is browser dependent and is usually 20-30 characters in length. It is strongly recommended that you set the size of a text window rather than using the default. This will allow you to effect the appearance of the form in a pleasing and useful manner. Further, the appearance of the form will be fairly independent of the browser being used. The default window size is browser dependent and is usually 20-30 characters in length. However, you can set the size using style sheets or the size attribute. The maxlength attribute can be used to set the maximum number of characters that will be accepted by the control (field). You can use the value attribute to display a text inside the window, but this is optional. Code: <input type="text" name="text1" size="50"> Output: value The value attribute assigns an initial value, such as a text or number, to a form control (field). This can be changed later using script code. usemap This usemap attribute specifies the name of an image map that you wish to associate with the element. This indicates that the image is being used as a mouse-clickable client-side image map. Code: MY SAMPLE FORM: <p> <form method="post" enctype="multipart/form-data" action="next.asp"> <input type="button" name="btn2" value="click me" style="background-color:yellow;"> Button <p> <input type="checkbox" name="ckbx2" value="true"> Check Box <p> <input type="file" name="file2"> Attach a File <p> <input type="hidden" name="SocSecNum" value="123-45-6789"> <p> <input type="password"> Password <p> <input type="radio" name="radio2" value="one" checked> First Radio Button <br> <input type="radio" name="radio2" value="two"> Second Radio Button <br> <input type="radio" name="radio2" value="three"> Third Radio Button <br> <input type="radio" name="radio2" value="four"> Forth Radio Button <p> <input type="text" name="submit" name="text2" size="50"> Text <br> <input type="text" name="submit" name="text3" size="25"> Text <br> <input type="text" name="submit" name="text4" size="2"> Text <p> <input type="reset" value="Clear The Form" style="color:white; background-color:blue;"> Reset Button <br> <input type="submit" name="submit" name="submit2" onclick="submitform()" value="Submit" style="color:white; background-color:red;"> Submit Button Or Use An Image Submit Button <input type="image" src="images/submit.gif" onclick="submitform()" name="submitgif"> border="0" </form> <script language="JavaScript"> function submitform() { alert("Thank You For Submitting The Form") } </script> Output: MY SAMPLE FORM: Button Check Box Attach a File Password First Radio Button Second Radio Button Third Radio Button Forth Radio Button Text Text Text Reset Button Submit Button Or Use An Image Submit Button