I have an input field, and when I type in it, I want a div to be updated at the same time.

I have a script that works this way, but I've just copied it, and it uses very much code. So I want a very simple one to work. Here's what I've got so far:

JavaScript:

Code:
function goCheck() {

	var u_name = document.getElementById('username').value;

	if (u_name!="") {
	
		document.getElementById('output').innerHTML = "<h3>Please Wait, getting results....</h3>";

		var url = 'test1.php';
		var pars = 'output=normal&username='+u_name+'';
		
		var myAjax = new Ajax.Updater( 'output', url, { method: 'get', parameters: pars, onlyLatestOfClass:"htmlfetcher" });

	}

}

HTML:
Code:
<input type="text" id="username" size="25" onkeyup="goCheck();">						

<span id="output"><h3><font color="#D55121" face="arial">The usename will be here</font></h3></span>
What should I do to make this work?

Thanks in advance