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 = 'check.php?';
    if(handle.value.length > 0) {
        var fullurl = url + 'do=check_username_exists&un=' + encodeURIComponent(handle.value);
        http.open("GET", fullurl, true);
        http.send(null);
        http.onreadystatechange = statechange_username;
    }else{
        document.getElementById('username_exists').innerHTML = '';
    }
}

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 = html;
		if (html == 'This username already exists, please select another one.') {handle.value = '';}
    }
}

function msgprompt(msgstr)
{
    var hi= confirm(msgstr);
	return hi;
}