Availability control action

Hi experts,

I've customized the "Project Availability Control: Tolerance Limits" with the action 3 (Error Message). And when I introduce the actual hours of an activity the hours I get the message as I expected:

"Errors arose during actual cost calculation --> Budget for WBS element M3029DDD321 was exceeded by 1.000,00 EUR in document item 001 Ntwk actvty 4000347 0180 ."

The problem is that I am able to save the confirmation, I thought the system would not let me save as I had exceeded the budget. Is this normal?

Thanks in advanced.