Throttle cutting out?

Hi all, for some reason sometimes when I go to accelerate to overtake my revs suddenly drop then pick up again straight away like as if the throttle shut off, then came straight back in. this has happened 3 times now and id like to get it sorted incase whatever it is decides to pack up totally and leave me with no throttle!! any ideas??
thanks!

Sounds like the throttle position sensor/potentiometer, replacement fixes ..

ooh ok thanks mate! hope its not too expensive lol