IE = (navigator.appName=="Microsoft Internet Explorer" ? 1 : 0);
 NS = (navigator.appName=="Netscape" ? 1 : 0);
 bVer = parseInt(navigator.appVersion);
 
 var newWin=null;
 var browserName = navigator.appName;
 var browserVersion = parseInt (navigator.appVersion);
 var bMac = (window.navigator.userAgent.indexOf("Mac")>=0);
 var bNetscape4Mac = (browserName == "Netscape" && browserVersion == 4 && bMac);
 var bIE5 = (navigator.appVersion.indexOf ("MSIE 5.0") > 0)
 var bIE5Mac = (browserName == "Microsoft Internet Explorer" && bIE5 && bMac);
 
 function guestpop(htmlURL) {
          var htmlURLPath = 'http://www.guest-book.co.uk/book/' + htmlURL;
		  _params = "width=717,height=530,resizable=no,status=no,scrollbars=yes";
 
         if (bVer >= 4) {
                  _left = ( (screen.width-717) >>1 );
                  _top = ( (screen.height-530) >>1 );
         } else {
                  _top=45, _left=40;
         }
         if (IE) _params += ",top=" + _top + ",left=" + _left;
         else if (NS) _params += ",screenX=" + _left + ",screenY=" + _top;
 
                 
         	if (!bNetscape4Mac && !bIE5Mac)
	 	{
	 		if (newWin && !newWin.closed)
	 			newWin.close();
	 		 	
	 	}
	 newWin = window.open(htmlURLPath,"guest", _params);
	 
	 	if (!bIE5Mac)
	 		newWin.focus();
}
 
function leavePage()
{
	
if (newWin)
	newWin.close();

}