attach IDENTITY property to an existing column

Hi All,
Can any body tell me that how we can attach IDENTITY property to an existing int columnyou can not.

you have to...

1. rename the existing table
2. drop the foriegn keys referencing it.
3. drop the constraints on the renamed table.
4. define a new table with the identity property with the orginal table name
--the next 2 can go in any order based on what you decide is best
5. then reapply all constraints on the table, usually doing the primary key first.
6. insert data from the renamed table to the new table. you may want to do a INSERT IDENTITY MyTable ON to insert your existing keys. Just do not forget to turn it off when you are done.
7. drop the renamed table (optional)

you may want to wrap all or part of this in an explicit transaction with appropriate error handlers and print messages and you may not want to drop renamed table until you have committed the transaction without error and your row count after the insert matches the rowcount in the new table.