function newwin(location,name,w,h)
{
    var scrw=(screen.width/2)-(470/2);
    var scrh=(screen.height/2)-(270/2);
//    window.open(location,name,'scrollbars,left='+scrw+',top='+scrh+',width='+w+',height='+h);
    window.open("pop_mapa.php?m="+location,name,'width=470,height=270,resizable=no,status=no,menubar=no,top=0,left='+scrw+'top='+scrh);    
}