onkeydown event (Internet Explorer)

Switch View :

Classic

Lightweight

ScriptFree

Site Feedback

onkeydown event

[This documentation is preliminary and is subject to change.]

Fires when the user presses a key.

Syntax

HTML Attribute	<element onkeydown = "handler(event)">
Event Property	object.onkeydown = handler;
attachEvent Method	object.attachEvent("onkeydown", handler)
addEventListener Method	object.addEventListener("keydown", handler, useCapture)

Standards information

HTML 4.01 Specification, Section 18.2.3

Event information

Synchronous	No
Bubbles	No
Cancelable	No

Event handler parameters

pEvtObj [in]: Type: IHTMLEventObj

Remarks

You can cancel all keys that fire the onkeydown event in HTML Applications, including most accelerator keys, such as ALT+F4.

As of Microsoft Internet Explorer 5, the event also fires for the following keys:

Editing: BACKSPACE
Navigation: PAGE UP, PAGE DOWN
System: SHIFT+TAB

As of Internet Explorer 5, this event can be canceled for the following keys and key combinations by specifying event.returnValue=false:

Editing: BACKSPACE, DELETE
Letters: A - Z (uppercase and lowercase)
Navigation: PAGE UP, PAGE DOWN, END, HOME, LEFT ARROW, RIGHT ARROW, UP ARROW, DOWN ARROW
Numerals: 0 - 9
Symbols: ! @ # $ % ^ & * ( ) _ - + = < [ ] { } , . / ? \ | ' ` " ~
System: SPACEBAR, ESC, TAB, SHIFT+TAB

As of Microsoft Internet Explorer 4.0, the onkeydown event fires for the following keys:

Editing: DELETE, INSERT
Function: F1 - F12
Letters: A - Z (uppercase and lowercase)
Navigation: HOME, END, LEFT ARROW, RIGHT ARROW, UP ARROW, DOWN ARROW
Numerals: 0 - 9
Symbols: ! @ # $ % ^ & * ( ) _ - + = < [ ] { } , . / ? \ | ' ` " ~
System: ESC, SPACEBAR, SHIFT, TAB

In Internet Explorer 4.0, you cannot cancel the onkeydown event, but you can use the onkeypress event to cancel keyboard events.

Returns a number specifying the keyCode of the key that was pressed.

To invoke this event, do one of the following:

Press any keyboard key.

The pEvtObj parameter is required for the following interfaces:

HTMLAnchorEvents2
HTMLAreaEvents2
HTMLButtonElementEvents2
HTMLControlElementEvents2
HTMLDocumentEvents2
HTMLElementEvents2
HTMLFormElementEvents2
HTMLImgEvents2
HTMLFrameSiteEvents2
HTMLInputFileElementEvents2
HTMLInputImageEvents2
HTMLInputTextElementEvents2
HTMLLabelEvents2
HTMLLinkElementEvents2
HTMLMapEvents2
HTMLMarqueeElementEvents2
HTMLObjectElementEvents2
HTMLOptionButtonElementEvents2
HTMLScriptEvents2
HTMLSelectElementEvents2
HTMLStyleElementEvents2
HTMLTableEvents2
HTMLTextContainerEvents2
HTMLWindowEvents2
HTMLWindowEvents4

Examples

This example uses the onkeydown event to cancel input from the keyboard.

Code example: http://samples.msdn.microsoft.com/workshop/samples/author/dhtml/refs/onkeydown.htm


<script type="text/javascript">
function fnTrapKD(){
   if(oTrap.checked){
      oOutput.innerText+="[trap = " + event.keyCode + "]";
      event.returnValue=false;
   }
   else{
      oOutput.innerText+=String.fromCharCode(event.keyCode);
   }
}
</script>
<input type="checkbox" id="oTrap">
<input id="oExample" type="text" onkeydown="fnTrapKD()">
<textarea id="oOutput" rows="10" cols="50">
</textarea>