Building an array of checked checkboxes

["Bob P. Roche" <BRoche@xxxxxxxxxxxxxxxxx>]

I am building a screen where I need to verify if any changes were made 
when the user tries to leave the screen. I have list of checkboxes where 
codes are selected. I am trying to compare those to a copied set in a 
non-displayed DIV.  I am using prototypeJS for most of my javascript, but 
I am new to both javascript and prototypeJS. Trying to self teach, but I 
am not  big fan of the prototypeJS documentation. 

Here is what I am trying

My checkbox ID's are savecode and code. All boxes in each group have the 
same id.

        newcode = $$('#code:checked');
        savedcode = $$('#savecode:checked');

        if (savecode != newcode) {

        do something here;

        } 

This always says the are not equal. I think more than the input value is 
being pulled into my variables.