Need for 1.2.1 - Usernames only with characters A-Z

[pgt96drvr]

There has to be a small bit of code that I can input that will only allow A-Z characters for the registering of a username. I searched the forum and I can see where the adition of certain characters would cause errors, but I'm jsut looking to abolish all other characters instead.

Thanks guys.  I didn't put this in the paid section, becasue I don;t think that it will take too long for the code for this, but I am willing to pay a little if you would like.

Thanks.

[pgt96drvr]

Had a brain fart....   

If I go into the database and change the field of the username form "VARCHAR"  to "CHAR"  will this effect my current users with ">" and "<", etc. in their names?  I would flip the switch, but I don't want to mess anything up.

thanks.