Handling an AJAX response

[sdustinh]

Hey, I'm looking to handle an XML response depending on what's sent. Better than I can explain it, here's an example...

function stateChanged () {
    if (xmlHttp.readyState == 4) {
        var xmlDoc = xmlHttp.responseXML;
 
        if (xmlDoc.getElementsByTagName("error")) {
            alert('error');
        }
    }
}

Alright, the response will be either all in <a></a> or <b></b> tags, but if there is an error, it will return <error></error> with all of the errors inside. I'd like to set up an if/else that will detect if the response is <error></error> or if it's actually something I'm going to use.

I don't know how to differentiate the two though. What I have there in the if/else seems to always return true. Has anyone else had this problem or knows the solution? Thanks!

[acoder]

Check the length of the array returned by getElementsByTagName().