A way to reset the collision?

Is there away to reset the collision detection if the player is not airborne? I was thinking since the player only gets stuck occasionally and the collHit = 100% when the player is stuck, I know it says that the higher the number the better the collision is working, but its too good :) and sticks the player to the ground. Since i like to repeat myself is there a way to reset the CollHit value to 0 if the player is not airborne?