any one help me with a mastermind game??

Question

hey hey, im new here and to programming, but im trying to write a mastermind game.  I have some of it sorted.  I have the computer pick the colours using "random" and then they are stored in an array and are marked with a red peg if the guess colours are in the right place.  the thing i am stuck on is the white pegs.  can anyone help me?  just remember im new to programming so talk to me like im a retard...none of this complex stuff.  any help would be much appreciated.