Disable button on post back – working with validators

In the past I’ve written a post on how to disable a button on post back:

Disable button on past back

This works really nicely, until you try use this with ASP.NET Validators.

«January»
SunMonTueWedThuFriSat
28293031123
45678910
11121314151617
18192021222324
25262728293031
1234567