function toggle_username(userid) {
	if (window.XMLHttpRequest) {
		http = new XMLHttpRequest();
	} else if (window.ActiveXObject) {
		http = new ActiveXObject("Microsoft.XMLHTTP");
	}
	handle = document.getElementById(userid);
	var url = 'modules/Login/ajax.php?';
	if(handle.value.length > 0) {
		var fullurl = url + 'do=check_username_exists&username=' + encodeURIComponent(handle.value);
		http.open("GET", fullurl, true);
		http.send(null);
		http.onreadystatechange = statechange_username;
	}else{
		document.getElementById('username_exists').innerHTML = '<img src="images/loader.gif"/>';
	}
}

function statechange_username() {
	if (http.readyState == 4) {
		var xmlObj = http.responseXML;
		var html = xmlObj.getElementsByTagName('result').item(0).firstChild.data;
		document.getElementById('username_exists').innerHTML = '<img src="images/' + html + '"/>';
	}
}