var strMeasure = document.layers ? "" : "px";

function popup ( strURL, strWidth, strHeight ) {
	var strTopstyle = isIE() ? "top" : "screenY";
	var strLeftstyle = isIE() ? "left" : "screenX";
	var win = window.open( strURL, "_blank", "width=" + strWidth + ",height=" + strHeight + "," + strTopstyle + "=" + getVAlignCenter(strHeight) + "," + strLeftstyle + "=" + getAlignCenter(strWidth) + ",menubar=no,location=no,resizable=no,scrollbars=yes,toolbar=no" );
}

function isIE(){
	if(navigator.appName.charAt(0)=="M"){
		return true;
	}
	return false;
}

function getAlignCenter(strWidth) {
	return ( window.screen.width - parseInt(strWidth) ) / 2 + strMeasure;
}

function getVAlignCenter(strHeight) {
	return ( window.screen.height - parseInt(strHeight) ) / 2 + strMeasure;
}