DevGuru JavaScript OBJECT: Select



			OBJECT: Select The Select object represents a selection list in a Form object. As such, it must be declared inside <FORM> tags. The JavaScript runtime engine creates such an object for every selection list in a particular form, and assigns it to the Form's elements array. It is through this array that a particular Select object can be accessed, either by index-number or by its NAME attribute. PROPERTIES form Property This property is a reference to the parent form to which a particular Select object belongs. Syntax: object.form length Property This property contains the number of options in the selection list. For example, to refer to the length of the first Select object in the first form of the current document, you could use the following code: Code: document.forms[0].elements[0].length Syntax: object.length name Property This property consists of a string which gives the name of the selection. For example, to refer to the name of the first Select object in the first form of the current document, you could use the following code: Code: document.forms[0].elements[0].name Syntax: object.name options Property This property is an array of all the options in a particular Select object. There is one element (numbered in ascending order from zero) for each <OPTION> tag. Syntax: object.options selectedIndex Property This property, which is tainted by default, is an integer relating to the currently-selected option of a Select object. If, however, the Select object allows for multiple selections (i.e. when the <SELECT> tag includes the MULTIPLE attribute), the selectedIndex property will only return the index of the first option selected. For example, the following code would return the index of the selected option of a Select object called MySelect in MyForm: Code: document.myForm.mySelect.selectedIndex Syntax: object.selectedIndex type Property This property holds the type of the Select object, having the value "select-one" where only one option can be selected and "select-multiple" where multiple selections are possible. The following code could be used to determine the type of the first Select object of the first form of the current document: Code: document.forms[0].elements[0].type Syntax: object.type METHODS blur Method This method removes focus from a selection list. Syntax: object.blur() focus Method This method moves the focus to the specified selection list allowing the user to then select from it. Syntax: object.focus() handleEvent Method This method calls the handler for a specified event. Syntax: object.handleEvent(event) NOTE: The Select object also inherits the watch and unwatch methods from the Object object. EVENT HANDLERS onBlur EventHandler This event handler causes JavaScript code to be executed whenever a blur event occurs; i.e. whenever a window, frame or form element loses focus. Syntax: onBlur = "myJavaScriptCode" onChange EventHandler This event handler executes JavaScript code whenever a Select, Text or Textarea field loses focus after having been altered. Syntax: onChange = "myJavaScriptCode" onFocus EventHandler This event handler executes JavaScript whenever a focus event occurs; i.e. whenever the user focuse on a window, frame or frameset, or inputs to a form element. Syntax: onFocus = "myJavaScriptCode"