var xmlHttp=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;
}

function IsNumeric(sText)
{
   var ValidChars = "0123456789.";
   var IsNumber=true;
   var Char;


   for (i = 0; i < sText.length && IsNumber == true; i++)
      {
      Char = sText.charAt(i);
      if (ValidChars.indexOf(Char) == -1)
         {
         IsNumber = false;
         }
      }
   return IsNumber;
}

function getURL (url,fn)
{
	//alert(url);
	xmlHttp=GetXmlHttpObject();
	if (xmlHttp==null)
    {
      alert ("Your browser does not support AJAX!");
      return;
    }
    xmlHttp.onreadystatechange=fn;
    xmlHttp.open("GET",url,true);
    xmlHttp.send(null);
}

function displayResults()
{
    if (xmlHttp.readyState==4)
    {
	var xmlDoc=xmlHttp.responseXML.documentElement;
	var node = xmlDoc.getElementsByTagName("result");
	document.getElementById("chestsize").innerHTML = node[0].getAttribute("chestsize");
	document.getElementById("forearmsize").innerHTML = node[0].getAttribute("forearmsize");
	document.getElementById("waistsize").innerHTML = node[0].getAttribute("waistsize");
	document.getElementById("thighsize").innerHTML = node[0].getAttribute("thighsize");
	document.getElementById("hipsize").innerHTML = node[0].getAttribute("hipsize");
	document.getElementById("calvesize").innerHTML = node[0].getAttribute("calvesize");
	document.getElementById("bicepsize").innerHTML = node[0].getAttribute("bicepsize");
	document.getElementById("necksize").innerHTML = node[0].getAttribute("necksize");
    }
}

function calc(form)
{
	if ((form.wrist.value == '') || (! IsNumeric(form.wrist.value)))
	{
		document.getElementById("msg").innerHTML = "<b>Invaid wrist size</b>";
		return ;
	}

	var url = "grith.php?";
	url = url + "txtWrist=" + document.getElementById("wrist").value;
	for (i=0;i<form.rdbUnit.length;i++)
	 if (form.rdbUnit[i].checked)
 	    url = url + "&txtUnit=" + form.rdbUnit[i].value;
	document.getElementById("msg").innerHTML = '';
	getURL(url , displayResults);
}