Making cell inactive when a user updates a cell with y/n value

[Latha]

hello all,

i need your help...

i want to make some cells inactive when the user updates Yes/No value in another cell.

For example : A2 has a dropdown of Yes/No values. if the user selects Yes then he should be able to update in next cell. If user selects "No" then the next cell should be inactive.

Please guide me..

Thanks a lot in advance,
Latha

 

[Latha]

plz revert soon