Tcl help

I have an account number that is 13 digits long.  Sometimes that number comes across as all zero’s, or all ones or something like that.  I want to be able to check to see if all 13 digits are the same and if so, kill the message.   Right now, I’m using a switch statement that has:

0000000000000 –

1111111111111 –

2222222222222 –

…

9999999999999 { do something here }

I’ve been tinkering with the regexp but can’t find a combination that works, if it works at all.  Is there a less intensive way of doing this or is this switch the best solution there is?

Thanks….

Thomas G. Rioux

The Methodist Hospital