// JavaScript Document
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 = 'checkuser.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_result').innerHTML = '';
	}
}

function statechange_username() {
    if (http.readyState == 2) {
       var html = '<div id="checking">checking</div>';
        document.getElementById('username_result').innerHTML = html;
    }
	if (http.readyState == 4) {
        var xmlObj = http.responseXML;
        var result = xmlObj.getElementsByTagName('result').item(0).firstChild.data;
		if(result == 'Y')
		{
			var html = '<div id="available">The username is available</div>';
			document.getElementById('username_result').innerHTML = html;
		}
		else if(result == 'N')
		{
			var html = '<div id="notavailable">The username is already taken</div>';
			document.getElementById('username_result').innerHTML = html;
		}
    }
}