AS3 error: TypeError: Error #1006: value is not a function.

var addBTN:Button = new Button();
	addBTN.move(310,300);
	addBTN.label= "Add";
	box.addChild(addBTN);
	
	addBTN.addEventListener(MouseEvent.CLICK, addit);
	
	function addit (evt:MouseEvent):void {
		
	var addingRequest:URLRequest =  new URLRequest("http://localhost/addbooktest/addPerson.php");
	
	var addVariables:URLVariables = new URLVariables();
	addVariables.fname = fname.text;
	addVariables.lname = lname.text;
	addVariables.phone = phone.text;
	addVariables.email = email.text;
	trace(addVariables);
	
	addingRequest.data(addVariables);
	addingRequest.method = URLRequestMethod.POST;
	
	sendToURL(addingRequest);
 
}