Getting a cell value based on a pre-existing cell value dynamically

[abdelfattah]

hi, experts
i write data manually in column a, b what i want if i write duplicated data in column a then bring value in column b for instance i write theses data

a b
aa 123
bb 1234
cc 12345
then if i repeat this
aa should bring 123
if is possible do that by macro in worksheet event change
thanks advance

 

[Fluff]

Glad we could help & thanks for the feedback.