var gZc_wsurl;

function validatePostalCode(zctb, callback)
{
	var result = false;
	if(zctb && zctb.value && zctb.value.length == 5)
	{
		var xresult = MakeXMLHttpRequestCall(gZc_wsurl+ '/IsValidPostalCode', 'postalCode=' + zctb.value, false, null, null, null, null);
		if(xresult && xresult.firstNodeValue)
		{
			
			if (xresult.firstNodeValue == 'true')
				result = true;
		}
	}
	
	if(!result && typeof callback == 'function') callback();
	
	return result;
}