Program to call the js function - change in dropdown list made in ASP.NET MVC

Write a program to call the js function when the change is being made in the Dropdown list made in ASP.NET MVC?

- To call the function of the js (JavaScript) in the dropdown list in ASP.NET MVC the function has to be written like:
<script type="text/javascript">
function selectedIndexChanged() { }
</script>

- The function need to be called using the code nuggets or if the Razor view engine the the js has to be integrated as:

<%:Html.DropDownListFor(x => x.SelectProduct, new SelectList(Model.Products, "Value", "Text"), "Select product", new { id = "dpDown", onchange="selectedIndexChanged()" })%>