Haskell function that will replace all occurrences of a in list with b.

Write the function replace :: Eq a => a -> a -> [a] -> [a]. The application replace a b list will replace all occurrences of a in list with b.

For example:

replace a X "abcabAcdaee" ? "XbcXbAcdXee"

replace 1 100 [2,3,1,1,5,6] ? [2,3,100,100,5,6]