MS excel question

Hello,
I am having a name list in column A and category list in column D and I want to list names of same category in column G in another worksheet. Example
.Worksheet1. .Worksheet2.[Result I want]
Col. A Col. D Col.G{here I want only category 1}
a 1 a
b 2 d
c 3 g...and so on
d 1
e 2
f 3
g 1
h 2
i 3

Plz help.