Rails spinoffs - Aug 2006 - determining which button was clicked

hi, i''m not sure if this has already been discussed, but the forum 
interface search facility isn''t working due to ''technical
difficulties''
and i can''t find anything about it in google.

in Form.serialize there is nothing to tell you what button was clicked for 
a submit event. i''ve made the following change to prototype.js:

var form_submit_button_used = false;

var Form = {
   serialize: function(form) {
     var elements = Form.getElements($(form));
     var queryComponents = new Array();

     for (var i = 0; i < elements.length; i++) {

       var add_to_query = true;

       if(elements[i].type=="submit")
       {

if((elements[i].name!=form_submit_button_used)||(!form_submit_button_used))
               add_to_query = false;
       }

       if(add_to_query)
       {
           var queryComponent = Form.Element.serialize(elements[i]);

           if (queryComponent)
               queryComponents.push(queryComponent);
       }
     }

in order to use this, you have to set the form_submit_button_used variable 
to the name of the button that was clicked. i have implemented this 
function elsewhere, but it may be good to write a method called 
Form.prepareClickEvents or something like that so that it''s bundled as 
part of prototype:

forms = document.forms;

for(i = 0;i<forms.length;i++)
{
     for(j = 0;j < forms[i].elements.length;j++)
     {
         var curr = forms[i].elements[j];

         if(curr.type == "submit")
             curr.onclick = setSubmittedName;
     }
}

function setSubmittedName()
{
   form_submit_button_used = this.name;
}

cheers

iain