
The stock DropDown
control that comes with ASP.NET allows us to select only one item. To overcome this limitation, I wrote the MultiDropDown
ASP.NET Server Control that allows selection of multiple items from a checkable list of items. This control supports multiple instances in the same web page. The best part about this control is you do not have to add any other external files (like images, style sheets or JavaScript files) to your project, the control does everything automatically behind the scenes.
Read the full Article here at CodeProject.