Simple Merge Cells (Macro)

Hi,

Please i want some help to do one simple macro;

i have this table

eee1 eee2
1 a
1 a
1 b
1 b
1 c
1 c
1 e
1 e
1 e
1 e

and i want the macro to do the following output;

eee1 eee2
1 a
1
1 b
1
1 c
1
1 e
1
1
1

as rows A2,3 showing merged cells in column B as "a" in merged rows B2,3

it is big excel sheet, i mean the column B is very long and i need to merge sometimes 2,3.....20 cells togather.

please help