function toggleLayer(whichLayer)
{
if (document.getElementById)
{
// this is the way the standards work
var style2 = document.getElementById(whichLayer).style;
style2.display = style2.display? "":"block";
}
else if (document.all)
{
// this is the way old msie versions work
var style2 = document.all[whichLayer].style;
style2.display = style2.display? "":"block";
}
else if (document.layers)
{
// this is the way nn4 works
var style2 = document.layers[whichLayer].style;
style2.display = style2.display? "":"block";
}
}

<!--
function checkform ( form )
{

  // ** START **
  if (form.title.value == "") {
    alert( "Please enter a title for your review." );
    form.title.focus();
    return false ;
  }

  if (form.username.value == "") {
    alert( "Please enter an alias." );
    form.username.focus();
    return false ;
  }
  
    if (form.comments.value == "") {
    alert( "Please enter a review." );
    form.comments.focus();
    return false ;
  }
  
     if (form.location.value == "") {
    alert( "Please enter your location." );
    form.location.focus();
    return false ;
  }
  
  // ** END **
  return true ;
  
}
//-->