function openWindow (nameurl, namewindow, width, height){

    x = (640 - width)/2, y = (480 - height)/2;
    scrollb = 'yes';
    res = 'yes';
    if (screen) {
	y = (screen.availHeight - height)/2;
	x = (screen.availWidth - width)/2;
    	scrollb = 'yes';
	res = 'yes';
    }
    if ((namewindow == 'big') || (namewindow == 'highscore')) {
    	scrollb = 'yes';
	res = 'yes';
    }

    var prevwin = window.open(nameurl,namewindow,'width='+width+',height='+height+',screenX='+x+',screenY='+y+',top='+y+',left='+x+',scrollbars='+scrollb+',resizable='+res);
    prevwin.focus();
  }

<!--
function openBrWindow(theURL,winName,features) { //v2.0
  window.open(theURL,winName,features);
}