There is no each function on arrays.

As Anton points out in the comments, you don't need each at all for what you're doing; see below the fold.

But if you want each, you have three choices:

1. Wrap your array in a jQuery instance and use jQuery's each: $(formLevel2DDs).each(function(index, entry) { ... });




2. Use jQuery's $.each: $.each(formLevel2DDs, function(index, entry) { ... });

   
   
   

   Note that this is not the same function as above.




3. Use forEach (MDN | Spec): formLevel2DDs.forEach(function(entry, index, array) { ... });

   
   
   

   Note that forEach is new as of ECMAScript5. All modern browsers have it, but you'll need a shim/polyfill for older ones (like IE8). Also note that the order of the arguments to the callback is different than either of the options above.

But to Anton's point, you can do that much more simply:

There's no reason to use getElementById directly in this case, it's not in a tight loop or anything, so:

jQuery(document).ready(function() {



    $(#supplier, #formElementChargeRate, #formElementEmailIDS).change(validateForm);



});

Note that I've also removed the wrapper function from around validateForm. You may need to add it back if validateForm has a return value, and you don't want that return value to be used by jQuery (specifically: if it returned false, jQuery would stop propagation and prevent the default action of the change event).

If you really wanted to have direct access to the DOM elements using those variables:

jQuery(document).ready(function() {



    var drpSupplier, drpChargeRate, drpIDSEmail;

    var formLevel2DDs       = [

        drpSupplier         = document.getElementById('supplier'),

        drpChargeRate       = document.getElementById('formElementChargeRate'),

        drpIDSEmail         = document.getElementById('formElementEmailIDS')

    ];



    $(formLevel2DDs).change(validateForm);

});