function showOrHide(value) {
    if (value==0) {
        if (document.layers)
           document.layers["layer3"].visibility='hide';
        else
           document.all["layer3"].style.visibility='hidden';
   }
   else if (value==1) {
       if (document.layers)
          document.layers["layer3"].visibility='show';
       else
          document.all["layer3"].style.visibility='visible';
   }
}