Next name down a list

Hi

I need a formula/vba function that will select the next name down on a list and place it in another cell, lets say for example we have names in cells A1:A20 names go as follows:

DJ
DJ
DJ
AC
AC
FB
FB

Now starting in column b i want a formula/vba that will look for the next name down column a and place it in the cells so i get

DJ
AC
FB

Thanks in advance

DJ