var win = null;
  function abrirventana(mypage,myname,w,h,scroll)
  {
    LeftPosition = (screen.width) ? (screen.width-w): 0;
    TopPosition = (screen.height) ? (screen.height-h): 0;
    LeftPosition = 0;
    TopPosition = 0;
    settings =
'height='+h+',width='+w+',top='+TopPosition+',left='+LeftPosition+',scrollbars='+scroll+',resizable,titlebar=no'
    win = window.open(mypage,myname,settings)
    if(win.window.focus){win.window.focus();}
  }