Hi! I used this code it’s worked. But I want when Id exist then output any parameter equal 1 else 0. because I have two button Add and Continue.  

CREATE PROCEDURE InsertName
    @Id INT = NULL
    @Name VARCHAR(50)= ''
as
BEGIN
IF NOT EXISTS(SELECT Count(Id) FROM ParsonTable WHERE Id = @Id) OR @Id IS NULL
BEGIN
INSERT INTO ParsonTable(FirstName) VALUES(@Name)
SELECT 1
END
ELSE
    BEGIN
         UPDATE ParsonTable
         SET FirstName = @Name            
         WHERE Id = @Id
     SELECT 0
    END
 END

private void GetData(string name)
{
            SqlConnection con = new SqlConnection(str);
            SqlCommand cmd = new SqlCommand();
            cmd.CommandType = System.Data.CommandType.StoredProcedure;
            cmd.CommandText = "InsertName";
            cmd.Parameters.AddWithValue("@Name", 
            cmd.Connection = con;
            con.Open();
            try
            {
                cmd.ExecuteNonQuery();
            }
            catch { }
            con.Close();
}
protected void btnSearch_Click(object sender, EventArgs e)
{  
GetData(Name.Text);
If (parameter =  0)
{
btnAdd.Enabled = true;
}
else
{
btnContinue.Enabled = true;
}
}