nn4 = (document.layers)? true : false;
ie4 = (document.all)? true : false;
nn6 = (document.getElementById && !ie4)? true : false;

function popupWin(fileName, windowName, winWidth, winHeight) {
	if (nn4 || ie4 || nn6) {
		posX = Math.round ((screen.width - winWidth) / 2);
		if (!window.opera) {
			posY = Math.round ((screen.height - winHeight) / 2 - 35);
		} else {
			posY = Math.round ((screen.height - winHeight) / 2 - 80);
		}
		posCode = (nn4 || nn6)? "screenX="+posX+",screenY="+posY : "left="+posX+",top="+posY;
	} else {
		posCode = "";
	}
	newWindow = window.open(fileName,windowName,'menubar=no,toolbar=no,scrollbars=yes,status=yes,width='+winWidth+',height='+winHeight+','+posCode);
	newWindow.focus();
}