Negate a filter

[S�ren M. Olesen]

Hi
Is it possible to negate a filter. I.e. instead og letting matched througt, 
it should stop matched from getting through.

Lets say I want to remove lines containing the word SQL from my log, how do 
I setup a filter that will let all lines through, except lines containing 
the word SQL??

TIA

Søren