function send_email(product_id)
{

var from_name=document.getElementById("from_name").value; 
var from_email_address=document.getElementById("from_email_address").value; 
var to_name=document.getElementById("to_name").value; 
var to_email_address=document.getElementById("to_email_address").value;
var message=document.getElementById("message").value; 
var emailfilter=/^\w+[\+\.\w-]*@([\w-]+\.)*\w+[\w-]*\.([a-z]{2,4}|\d+)$/i

if ( (from_name == '') || (from_email_address == '') ||(to_name == '') ||(to_email_address == '') ||(message == ''))
  { 
   if(from_name == '')
    { 
      document.getElementById("form_check_result").innerHTML="Your name is missing";
      return;
    }
    else if(from_email_address == '')
    {
      document.getElementById("form_check_result").innerHTML="Your email is missing";
      return;
    }
    else if(to_name == '')
    {
      document.getElementById("form_check_result").innerHTML="Your freind's name is missing";
      return;
    }
    else if(to_email_address == '')
    {
     document.getElementById("form_check_result").innerHTML="Your freind's email is missing";
     return;
    }
    else if(message == '')
    {
      document.getElementById("form_check_result").innerHTML="Your message is missing";
      return;
    }
  }
 
 if( emailfilter.test(from_email_address) == false)
 
 {
  document.getElementById("form_check_result").innerHTML="Your email format is invalid";
  return; 
 }
 if( emailfilter.test(to_email_address) == false)
  
  {
   document.getElementById("form_check_result").innerHTML="Your friend's email format is invalid";
   return; 
 }
  var passData ='products_id='+product_id+'&yourname='+from_name+'&youremail='+from_email_address+'&yourfname='+to_name+'&yourfemail='+to_email_address+'&message='+message;
		var AJAX = null;
		if (window.XMLHttpRequest) {
		   AJAX=new XMLHttpRequest();
		} else {
		   AJAX=new ActiveXObject("Microsoft.XMLHTTP");
		}
		if (AJAX==null) {
		   alert("Your browser doesn't support AJAX.");
		   return false;
		} else {
		   AJAX.open("POST", "send_friend_message.php", true);
		   AJAX.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
		   AJAX.onreadystatechange = function() {
		      if (AJAX.readyState==4 || AJAX.readyState=="complete") {
                     document.getElementById("form_check_result").innerHTML=AJAX.responseText;
		      }
		   }
		   AJAX.send(passData);
	      }
}