popup
IE = navigator.appName=="Microsoft Internet Explorer";
NS = navigator.appName=="Netscape";
bVer = parseInt(navigator.appVersion);

var newWin=null;

function popup(loc, name, width, height) {
        var _params = "width="+width+",height="+height+",resizable=no,status=yes,scrollbars=yes";

        
        if (bVer >= 4) {
                 _left = ( (screen.width-width) >>1 );
                 _top = ( (screen.height-height) >>1 );
        } else {
                 _left = ( (600-width) >>1 );
                 _top = ( (420-height) >>1 );
        }

        if (IE) _params += ",top=" + _top + ",left=" + _left;
        else if (NS) _params += ",screenX=" + _left + ",screenY=" + _top;

        newWin = window.open(loc, name, _params);
        if ( newWin!=null && !(IE && bVer<5) )
                newWin.focus(); 
}