function show_compi(filename)
{
  switch(screen.width)
  {
   case 800:
     window.open(filename, "popup", "width=480,height=500,top=0,left=300,toolbar=no,locationbar=no,scrollbars=yes,resizable=yes");
     break;
   case 1024:
     window.open(filename, "popup", "width=480,height=560,top=0,left=500,toolbar=no,locationbar=no,scrollbars=yes,resizable=yes");
     break;
   case 1152:
     window.open(filename, "popup", "width=480,height=660,top=0,left=652,toolbar=no,locationbar=no,scrollbars=yes,resizable=yes");
     break;
   case 1280:
     window.open(filename, "popup", "width=480,height=660,top=0,left=780,toolbar=no,locationbar=no,scrollbars=yes,resizable=yes");
     break;
   case 1600:
     window.open(filename, "popup", "width=480,height=660,top=0,left=1100,toolbar=no,locationbar=no,scrollbars=yes,resizable=yes");
     break;
   default:
     window.open(filename, "popup", "width=480,height=540,top=0,toolbar=no,locationbar=no,scrollbars=yes,resizable=yes");
     break;
  }
}

function show_pic(filename, pic_width, pic_height)
{
  window.open(filename,"_blank","width="+pic_width+",height="+pic_height+",top=20,toolbar=no,locationbar=no,scrollbars=no,resizable=no")
}

function show_instr(filename)
{
  window.open(filename, "instr", "width=640,height=620,top=0,left=0,toolbar=no,locationbar=no,scrollbars=no,resizable=yes");
}