ComboBox entries at runtime

One approach would be to overlay the textbox portion of the dropdown with an actual textbox. In code, then, you'd need to keep the two in sync by copying the selected item in the dropdown to the textbox when the selection changes and adding and entered text to the listitems in the dorpdown.

You didn't mention whether you were doing ASP.Net or winforms. I'm assuming you're talking about web forms. If Winforms, then have a look at the DropDownStyle property of the drop down control.

Mitch Gordon
http://www.enterpriseetc.com