Merge ASP.Net GridView Rows

how to merge grid view on the basis of some condition........

for e.g i hv table given below........

A1                  A2                      A3

Level Of -

Information

ss                     ss                   ss

aa                     aa                  aa

Amit

al                      al                     al

Now in case of "Level Of -Information" and "Amit" column A2 and A3 are blank.........

I want these rows to merge

Thanks in advance...................