For some reason I didn't load the ScriptManager dynamically. So, make sure you include a ScriptManager on the page before using the usercontrol or you will come across this error message: "The control with ID 'HoverMenuExtender1' requires a ScriptManager on the page. The ScriptManager must appear before any controls that need it."

" Invalid postback or callback argument. Event validation is enabled using…".

Initially, I was trying to modify the value of the dropdownlist through the JavaScript and I kept getting the error whenever I hit the submit button. The easiest solution was to set the EnableEventValidation = false on the page directive, but instead, I found another work around by using hidden field.

The tooltip (title) were displaying correctly on IE 7.0, 8.0, FireFox and Google Chrome but not in IE6.0. In order to remedy the problem, I included a separate function to show and hide the tooltip.

I am using a checkboxlist controls and having difficulty to get the checkboxlist value and text using JavaScript. After conducting some research, I came across a class library by Trilochan Nayak. I have modified his class so that I can retrieve the value and text of the selected checkbox through the JavaScript.