How to add an onchange event to a select box via javascript?

I've got a script where I am dynamically creating select boxes. When those boxes are created, we want to set the `onchange` event for the new box to point to a function called `toggleSelect()`. I can't seem to get the syntax right to create the `onchange` event. Can someone tell me what I'm doing wrong? It doesn't throw an error, but doesn't work, either. ``` col = dataRow.insertCell(0); var transport_select = document.createElement('select'); transport_select.id = transport_select_id; transport_select.options[0] = new Option('LTL', 'LTL'); transport_select.options[1] = new Option('FTL', 'FTL'); transport_select.onChange = function(){toggleSelect(transport_select_id);}; col.appendChild(transport_select); ```