Convert Row as Colum in SQL Server

Hi..

How make columns dynamically in sql server query at runtime

for example

Product    Months    values

A              APR         5

A              APR         9

B              APR         8

A              MAY        7

B              MAY        5

C              MAY        5

I want result set as like below

Product         APR             MAY

A                   14               7

B                    8                5

C                   ---              5