show/hide element by name

Use the 'id' of the element to do the same.

var s = document.getElementById('results').style;
var b = document.getElementById('buttonId');
if(!s || !b)
   return;
b.onclick = function() {
   s.display = 'none';
};

I just changed things a couple hours ago and echo'd a div with the 'username' as the id before the <p> element, then referenced that id in the onreadystatechange of an ajax function(calls an update to the database when a button is clicked) to set it to hidden once the update is complete.

function confirmuser(user) {
	htmlRequest = ajaxFunction();
	var params = "user="+user;
	var getid = document.getElementById(user);
	if (htmlRequest==null){ // If it cannot create a new Xmlhttp object.
		alert ("Browser does not support HTTP Request");
		return;
	} 
	htmlRequest.open('POST', 'confirmuser.php');
	htmlRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	htmlRequest.setRequestHeader("Content-length", params.length);
	htmlRequest.setRequestHeader("Connection", "close");
	htmlRequest.onreadystatechange = function() {//Call a function when the state changes.
	if(htmlRequest.readyState == 4 && htmlRequest.Status == 200) {
		getid.style.display = 'none';
		}
	}
	htmlRequest.send(params); 
}

Thanks though :)