AJAX & PHP -Retrieving more than one value - php

Question

I'll get to the point, assume my PHP script returns an array with two values, how would I address them within javascript?
<script type="text/javascript">
function ValidateCard(cardno)
{
if (cardno.length==0)
{
document.getElementById("txtprice").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else
{// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtprice").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","coding/validation/validatecard.php?cardno="+cardno,true);
xmlhttp.send();
}
</script>
As you can see whatever is returned is send to display within a div tag, how would I differentiate between data?
Thanks

Answer 1

You could use json to serialize it so that javascript can read it.
So, in php json_encode($arr);
http://www.php.net/manual/en/function.json-encode.php
Then in javascript.
you should be able to do something like jsarr[key] to get the values

Answer 2

<?php
$result = array('success'=>1, 'messgae'=>"the message you want to show");
echo json_encode($result);
?>
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
result = xmlhttp.responseText.evalJSON(true);
//you can use result as array to get the information you want to check
if (result['success']) {
document.getElementById("successs").innerHTML=result['message'];
}
}
}