function calculate_function(u){
			var responsetext=calculate_ajax(u,document.getElementById("sale_price").value, document.getElementById("down_percent").value, document.getElementById("year_term").value, document.getElementById("annual_interest_percent").value);
			//document.getElementById("send_email_display").innerHTML="Your email has been sent." + responsetext;
			}
			
		var xmlhttp
		
		function calculate_ajax(u,f1,f2,t1,t2)
		{
		xmlhttp=GetXmlHttpObject();
		if (xmlhttp==null)
		  {
		  alert ("Your browser does not support XMLHTTP!");
		  return;
		  }
		var url='';
		url="mortgage_calculator.php";
		if(u=='1'){
			url=url+"?form_complete="+u+"&sale_price="+f1+"&down_percent="+f2+"&year_term="+t1+"&annual_interest_percent="+t2;
			}
		else{
			url=url+"?form_complete="+u+"&idn=<?php echo $idn;?>" ;
			}
		url=url+"&amp;sid="+Math.random();
		xmlhttp.onreadystatechange=stateChanged;
		xmlhttp.open("GET",url,true);
		xmlhttp.send(null);
		}
		
		function stateChanged()
		{
		if (xmlhttp.readyState==4)
		  {
		  document.getElementById("TB_ajaxContent").innerHTML=xmlhttp.responseText;
		  }
		else{
			document.getElementById("TB_ajaxContent").innerHTML='Calculating...';
			}
		}
		
		function GetXmlHttpObject()
		{
		if (window.XMLHttpRequest)
		  {
		  // code for IE7+, Firefox, Chrome, Opera, Safari
		  return new XMLHttpRequest();
		  }
		if (window.ActiveXObject)
		  {
		  // code for IE6, IE5
		  return new ActiveXObject("Microsoft.XMLHTTP");
		  }
		return null;
		}