Please try the following.
SQL
CREATE PROC ContactCreateOrUpdate
@ContactID INT,
@Name VARCHAR(50),
@Mobile VARCHAR(50),
@Address VARCHAR(50),
@EmailID VARCHAR(50)
AS
BEGIN
IF (@ContactID = 0)
BEGIN
INSERT INTO Contact
(
Name,
Mobile,
Address,
[Email ID]
)
VALUES
(@Name, @Mobile, @Address, @EmailID);
END;
ELSE
BEGIN
UPDATE Contact
SET Name = @Name,
Mobile = @Mobile,
Address = @Address,
EmailID = @EmailID
WHERE ContactID = @ContactID;
END;
END;