Upsell Selection on an Upsell Page (For Devs)

You may have an upsell page displaying multiple products instead of one product.

Include the following javascript on the upsell page:

    function selectProduct(i)
      {
       document.getElementById('productIdInput').value = i;
       kform.validator.formSubmit();
      }

Inside of the form tag include:

<input id="productIdInput" name="productId" value="" type="hidden">

Wrap the button in div:

<div onclick="selectProduct(35)"></div>

35 in this example is the campaign product ID number.