 <p>I could not get the asp:DropdownList to fire the SelectedIndexChanged event. So this is how I completed the task.</p> <p>Adding the dropdown dynamically as shown above and adding the change event that calls a javascript:</p> <pre><code> onchange='UpdateLocationList()' </code></pre> <p>This function had to be put in a .js file. This web site had a .js file already. It also had some AJAX calls that I used to complete the task. In the UpdateLocationList(), I get the ID of the service type that was set as a value attribute in the dropdown. Then I use a function that is already part of the .js file to the LocationDetails page using the Service Type ID to display only the facilities of that service type. This is the function:</p> <pre><code> function updateLocationList() { var ddlFacilityType = document.getElementById("FacilityTypeDDL"); var facilityValue = ddlFacilityType.options[ddlFacilityType.selectedIndex].value; processAjax("/editor/Locations.aspx?Location_ID=" + facilityValue, "navPanel"); } </code></pre> <p>Works like a charm. </p> <p>Thanks for all of your help.</p>