Edit and Add are very similar, they both need to Save data to the server. The major difference between the two is that for Add you won't have a primary key for your data yet.
So you could have a single stored procedure called 'save' that you call on either edit or add, but the operation the procedure takes depends on whether or not you pass a primary key to it.
CREATE PROCEDURE myarea_SaveData
(
@PrimaryKey INT,
@FirstName VARCHAR(50),
@LastName VARCHAR(50)
)
AS
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED
SET NOCOUNT ON
IF EXISTS(SELECT FirstName FROM MyTable (NOLOCK) WHERE PrimaryKeyID = PrimaryKey)
BEGIN
UPDATE
MyTable
SET
FirstName = @FirstName,
LastName = @LastName,
WHERE
PrimaryKeyID = @PrimaryKey
END
ELSE
BEGIN
INSERT INTO
MyTable (PrimaryKey, FirstName, LastName)
VALUES
(@PrimaryKey, @FirstName, @LastName)
END
GO