// A utility function that returns true if a string contains only
   // whitespace characters.
   function isblank(s)
   {
       for(var i = 0; i < s.length; i++) {
           var c = s.charAt(i);
           if((c != ' ') && (c != '\n') && (c != '\t')) return false;
       }
       return true;
   }

   // This is the function that performs form verification.  It will be
   // involved from the onSubmit() event handler.  The handler should
   // return whatever value this function returns.
   function verify(f)
   {
       var msg;
       var empty_fields = "";
       var errors = "";
       // Loop through the elements of the form looking for blank fields.
       for (var i = 0; i < f.length; i++) {
           var e = f.elements[i];
           if((e.type == "text") && isblank(e.value) ||
                (e.type == "password") && isblank(e.value)) {
                    empty_fields += "\n " + e.name;
             }

       }

       // If any of the fields were blank report the blank fields and return
       // user to form.  Otherwise allow form to be submitted.
       if(empty_fields) {
           msg = "Oops!  Some of the text fields have been left blank!\n";
           msg += "Please fill the following fields:\n " + empty_fields + "\n";
            alert(msg);
           return false;
       }
    return true;
    }
    
function ff(that){
  if(that.style){ that.style.backgroundColor="#ffff00"; }
}

function fb(that){
  if(that.style){ that.style.backgroundColor="#ffffff"; }
}