function popup(theurl,winname,features, mywidth, myheight, iscenter) { //v3.0
  if(window.screen)if(iscenter)if(iscenter=="true"){
	var myleft = (screen.width-mywidth)/2;
    var mytop = (screen.height-myheight)/2;
    features+=(features!='')?',':'';
    features+=',left='+myleft+',top='+mytop;
  }
  window.open(theurl,winname,features+((features!='')?',':'')+'width='+mywidth+',height='+myheight);
}