How can I force input to uppercase in an ASP.NET textbox?

Question

I'm writing an ASP.NET application. I have a textbox on a webform, and I want to force whatever the user types to upper case. I'd like to do this on the front end. You should also note that there is a validation control on this textbox, so I want to make sure the solution doesn't interfere with the ASP.NET validation.

Clarification: It appears that the CSS text transform makes the user input appear in uppercase. However, under the hood, it's still lower case as the validation control fails. You see, my validation control checks to see if a valid state code is entered, however the regular expression I'm using only works with uppercase characters.

Answer 1

Why not use a combination of the CSS and backend? Use:

style='text-transform:uppercase'  

on the TextBox, and in your codebehind use:

Textbox.Value.ToUpper(); 

You can also easily change your regex on the validator to use lowercase and uppercase letters. That's probably the easier solution than forcing uppercase on them.