var resObject = null;
var dateObj = new Date(); //no caching for ajax object

function createReqObj()
{
	var resObject = null;

	try
	{
		resObject = new ActiveXObject("Microsoft.XMLHTTP");
	}
	catch(Error)
	{
		try
		{
			resObject = new ActiveXObject("MSXML2.XMLHTTP");
		}
		catch(Error)
		{
			try
			{
				resObject = new XMLHttpRequest();
			}
			catch(Error)
			{
				//alert("can't create XMLHttpRequest Object");
			}
		}
	}
	return resObject;
}

resObject = createReqObj();

function validatePLZ(plz, land)
{
	//alert(plz + ' # ' + land);

	resObject.open('get', 'plz_api/validate_plz.php?plz=' + plz + '&land=' + land, false);

	resObject.setRequestHeader("If-Modified-Since", dateObj.toGMTString());
	resObject.send(null);

	if(resObject.readyState == 4)
	{
		//alert("RES: " + resObject.responseText + " <<<<");

		var result = resObject.responseText.split('|');

		if(result[0] == 'true')
		{
			return new Boolean(true);
		}
		else
		{
			alert(result[1]);
			return new Boolean(false);
		}
	}
}