function openpop(URL,W,H,SR){
	L = parseInt((window.screen.width - W) / 2);
	T = parseInt((window.screen.height - H) / 2);
	var Wnd = window.open(URL, "", "left=" + L + ",top=" + T + ",width=" + W + ",height=" + H + ",toolbar=no,resizable=no,location=no,directories=no,status=no,menubar=no,scrollbars=" + SR);
}

function isNull(vValue, vDefault)
{
	if (typeof(vDefault) == "undefined")
	{
		if (typeof(vValue) == "undefined" || vValue == null)
			return true;
		else
			return false;
	}
	else
	{
		var vTmp;

		if (typeof(vValue) == "undefined" || vValue == null)
			return vDefault;

		vTmp = String(vValue);
		if (vTmp == "undefined" || vTmp == "" || vTmp == "null")
			return vDefault;

		return vValue;
	}
}