var xmlHttp;

function getHTTPRequestObject()
{

try
  {
  // Firefox, Opera 8.0+, Safari
  xmlHttp=new XMLHttpRequest();
  }
catch (e)
  {
  // Internet Explorer
  try
    {
    xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    }
  catch (e)
    {
    try
      {
      xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
      }
    catch (e)
      {
      alert("Your browser does not support AJAX!");
      return false;
      }
    }
  }

  }

function performAction(){

	if(xmlHttp.readyState==4)
      {
			alert(xmlHttp.responseText);
      }
	
  }

function doTask(url,vars){

	if(checkSendMailForm()){

	getHTTPRequestObject();

	xmlHttp.onreadystatechange=performAction;
	xmlHttp.open("GET",url+vars,true);
	xmlHttp.send(null);

	}

  }

  function checkSendMailForm(){

	var miss_fields;
	if(document.forms['MailForm'].sender_name.value==''){
		alert('your name is missing');
		return false;
	}
	else if(document.forms['MailForm'].email.value==''){
		alert('your_friend@email is missing');
		return false;
	}

	return true;
}