function postageCal(postcode,membership)
{
	var radio = membership;
	var isChecked = false;
	var months_fee_3 = 149.85;
	var months_fee_1 = months_fee_3/3;
	
	for (var i=0; i<radio.length; i++) {
		if (radio[i].checked == true) {
			var mem_fee = months_fee_3*(i+1);
			var isChecked = true;			
			break;
		}
	}
	
	if (isChecked == false) {
		alert ("Please select a membership.");
	}else{
	
		xmlHttp=GetXmlHttpObject();
		if (xmlHttp==null)
			{
			alert ("Your browser does not support AJAX!");
			return;
			} 
		var url="postage_cal.php";
		url=url+'?postcode='+postcode;
		
		xmlHttp.onreadystatechange=function()
		{
			if (xmlHttp.readyState==4)
			{ 			
			document.getElementById("total1").value=Math.round(Number(xmlHttp.responseText)*mem_fee*100/months_fee_1)/100;
			document.getElementById("total2").value=Math.round(Number(xmlHttp.responseText)*100)/100;
			document.getElementById("total3").value=Math.round((Number(document.getElementById("total1").value)+mem_fee)*100)/100;
			document.getElementById("total4").value=Math.round(Number(document.getElementById("total3").value)/mem_fee*months_fee_1*100)/100;
			}
		}
		xmlHttp.open("GET",url,true);
		xmlHttp.send(null);
	}
}

function GetXmlHttpObject()
{
var xmlHttp=null;
try
  {
  // Firefox, Opera 8.0+, Safari
  xmlHttp=new XMLHttpRequest();
  }
catch (e)
  {
  // Internet Explorer
  try
    {
    xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    }
  catch (e)
    {
    xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
  }
return xmlHttp;
}