no sound on powerbook

i reset my powerbook and now i have no sound! when i press F4 of F6 to change the volume the little picture pops up to confirm that you pressed the button and it shows the volume at max but there is a crossed out circle underneath it.

and when i check it in the preference pane it shows the volume slider as grayed out and also in the menu bar it is grayed!

does anyone know whats wrong?

i dont think so because under the preference pane under sound, it says Output Volume the slider is moved to max volume and the bar is grayed then you look over and see the mute check box that is unchecked and also grayed

wow! thanks! that worked perfectly!

now uh... y did it work?