Prompt user about pending changes
<p>I have a ASP.NET page, where I have couple of editable dropdowns, few editable textboxes and few display only fields.</p>

<p>I want to track whether user changed any dropdown values or textbox values. When user click goBack button, I want to prompt them with a message that the changes are not saved and if they really want to go back.</p>

<p>Please let me know what is the easiest way to track the changes on textbox or dropdwon list.</p>

<p>Thanks</p>
