Sending URL, how do tell if it was successfull?

So I want to send this url string and then once it has been sent and accepted I want to tell Flash to do something else… This is what I have right now as far as sending a url string. I’m at a loss for what I need to do to determine whether or not it has been received on the other end.

Here is my code:

var tagTerm = txtTag.text;

function tagImage(){
    var tagTerm = txtTag.text;
    var tagURL ="blahblahblah";
    var tagArt:LoadVars = new LoadVars();
    // do this once url has been send and recieved