var intUserNameMinSize = 5;
var intUserNameMaxSize = 20;
var elemUserName, elemUserNameStatus;

function checkUserNameStatus(){
	if(!elemUserName){ elemUserName = document.getElementById('userName'); }
	if(!elemUserNameStatus){ elemUserNameStatus = document.getElementById('userNameStatus'); }
	var len = elemUserName.value.length;
	if(len<intUserNameMinSize){
		elemUserNameStatus.innerHTML = "<i class='icon-warning-sign red'></i> too short";
		return;
	}
	if(len>intUserNameMaxSize){
		elemUserNameStatus.innerHTML = "<i class='icon-warning-sign red'></i> too long";
		return;
	}	
	doAjaxRequestUsernameAvailable('/gateway/username_available.php?userName=' + elemUserName.value, 'GET', true, updateUserNameStatus);	
}


var signup_xmlhttp;

function updateUserNameStatus(){
	//callback for the ajax request
	if (signup_xmlhttp.readyState == 4) {
		elemUserNameStatus.innerHTML = signup_xmlhttp.responseText;
	}
}



//just keeping things standalone
function doAjaxRequestUsernameAvailable(strURL,strGETorPOST,bAsync,callbackFunction){
	//makes an ajax request
	//if callbackFunction is provided, the request will be asynchronus
	//else the call is sync and we return the html result
	if (window.XMLHttpRequest){
		// code for IE7+, Firefox, Chrome, Opera, Safari
		signup_xmlhttp=new XMLHttpRequest();
	}else{
		// code for IE6, IE5
		signup_xmlhttp=new ActiveXObject('Microsoft.XMLHTTP');
	}
	if(strGETorPOST=='GET'){
		signup_xmlhttp.open('GET',strURL,bAsync);
		if(bAsync) signup_xmlhttp.onreadystatechange = callbackFunction;
		signup_xmlhttp.send();	
	}else if(strGETorPOST=='POST'){
		var i = strURL.indexOf('?');
		var strParams = '';
		if(i!=-1){
			strParams = strURL.substr(i+1);
			strURL = strURL.substr(0,i);
		}
		signup_xmlhttp.open('POST',strURL,bAsync);
		if(bAsync) signup_xmlhttp.onreadystatechange = callbackFunction;
		signup_xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		signup_xmlhttp.setRequestHeader("Content-length", strParams.length);
		signup_xmlhttp.setRequestHeader("Connection", "close");
		signup_xmlhttp.send(strParams);	
	}else{
		alert('Invalid usage - must provide GET or POST');
	}
	if(bAsync) return;
	
	var html;
	if(signup_xmlhttp.status==200){
		html = signup_xmlhttp.responseText;
	}else{ 
		html = 'HTTP Status ' + signup_xmlhttp.status + ' from ' + strURL ;
	}
	return(html);
}