C# Windows Form. When we create a new client ID for our client table, we would like to be able to select a valid code from the codes table and then have the sytem generate the unique 3 character sequence for the code. For instance, 2 valid codes are 10 (reinsureance company) and 20 (other company). In our current Visual FoxPro system the user can type 10 in the text box or click the pickbox icon to the right of the text box to select 10 from the list of valid codes. Either action triggers a system routine that generates the next 3 characters and displays it in the text box. Example: for the code of 10, the next available 3 digits are 463, so the new client ID would be 10463. I am new to C# and cannot find a simple way to do this to emulate the current routine in Visual FoxPro.