Error opening URL

Flash CS3 Actionscript 2.0

var senderLoad:LoadVars = new LoadVars();
var recieveLoad:LoadVars = new LoadVars();
Sender.onRelease = function() {
 senderLoad.theName = theName.text;
 senderLoad.theGladiatusName = theGladiatusName.text;
 senderLoad.theEmail = theEmail.text;
 senderLoad.theSubject = theSubject.text;
 senderLoad.theMessage = theMessage.text;
 senderLoad.sendAndLoad("http://ultimate-signatures.com/form.php", recieveLoad);
}
recieveLoad.onLoad = function(){
 if(this.$sentOK) {
  _root.gotoAndStop(300);
 }
 else{
  _root.gotoAndStop(305);
 }
}

Response - Error opening URL ‘http://ultimate-signatures.com/form.php

PHP

<?PHP 
$sendto = "[EMAIL="thelegion@ultimate-signatures.com"]thelegion@ultimate-signatures.com[/EMAIL]";
$subject = "The Legion Contact Forum";
$message = "Name: " . $theName; 
$message .= "
GladiatusName: " . $theGladiatusName;
$message .= "
Email: " . $theEmail;
$message .= "

Subject: " . $theSubject;
$message .= "
Message: " . $theMessage;
$headers = "From: $theEmail";
$headers .= "
Reply-To: $theEmail";
sentOK = mail($to,$subject,$message,$headers);
echo "sentOK=" . $sentOK;
?>

Please can someone let me know where im going wrong…

Thanks in advance
Andy