How to write an update statement for an update operation? (dealing with concurrency)

Question

hi,
Assume i have a method updateCustomer(DataSet ds),
typicaly we need to map the DataAdapter's UpdateStatement property to a storeprocedure or SQL query that has an update statement, If i write a Storped Procedure, it should take at least one input parameter.
This is where the problem is: when assining a value to the input parameter i should that should row updates
i.e: da.selectCommand.parameters["custIndex"].Value = "<customer index value>", but how do i know which row that was updated on the DataGridView?