File Under: JavaScript

JavaScript Event – Keyup

This code was written based on a template by John Resig. The original can be found at John Resig’s addEvent function website.

The code, and the template, are referred to in Webmonkey’s JavaScript Events reference page. In this example, the onKeyup event fires when a key is release while the target field has focus. The distiction between keyup and keydown is that keyup fires after the value of the key is added to a field.

You can also set the target to be the entire window to catch the keyup event globally.

The Code




// addEvent function by John Resig:


function addEvent( obj, type, fn ) {

  if ( obj.attachEvent ) {

    obj['e'+type+fn] = fn;

    obj[type+fn] = function(){obj['e'+type+fn]( window.event );}

    obj.attachEvent( 'on'+type, obj[type+fn] );

  } else

    obj.addEventListener( type, fn, false );





<!-- HTML for example event goes here -->

<input id="mytext" type="text" />

<br /><div id="mydiv" style="border: 1px solid black; width: 100px; height: 100px; margin-top: 10px;"></div>


// Script for example event goes here

addEvent(document.getElementById('mytext'), 'keyup', function(event) {

	display_short('keyup: ' + event.keyCode);


function display_short(str)



	document.getElementById('mydiv').innerHTML = str;

	if (str != '')

		setTimeout("display_short('')", 1000);





What it Looks Like