Forum:Increase permantly or decrease?

when you have a card effect like mage power where it increases attack by the number of spell/trap cards you control when you activate it does the attack of the monster go down when those other cards go to the graveyard or will it always keep the new attack and incrase if a new spell/trap is played?98.30.124.29 08:10, June 13, 2010 (UTC)ＪＡＳＯＮ