ASP.NET DataGridView Update

Question

Sir, I want your help in Update function in ASP.NET.

I providing you my code in order.

1)SQL Stored Procedure:-

ALTER PROCEDURE classEdit
@classId numeric(18,0),
@className varchar(20),
@noOfSeats int
AS


if NOT EXISTS (SELECT className FROM tbl_Class WHERE className=@className)
BEGIN
UPDATE tbl_Class
SET
className=@className,
noOfSeats=@noOfSeats
WHERE classId=@classId
END
ELSE if EXISTS (SELECT className FROM tbl_Class WHERE classId=@classId AND className=@className)
BEGIN
UPDATE tbl_Class
SET

noOfSeats=@noOfSeats
WHERE classId=@classId
END
ELSE
BEGIN
return -1
END

2) classInfo.cs:-

public class classInfo
{
    public decimal classId
    {
        get;
        set;
    }
    public string className
    {
        get;
        set;

    }
    public int noOfSeats
    {
        get;
        set;
    }
}


3) ClassSP.cs:-

public void classEdit(classInfo infoClass)
    {
        try
        {
            if (sqlCon.State == ConnectionState.Closed)
            {
                sqlCon.Open();
            }
            SqlCommand sqlCmd = new SqlCommand("classEdit", sqlCon);
            sqlCmd.CommandType = CommandType.StoredProcedure;
            sqlCmd.Parameters.Add("@classId", SqlDbType.Decimal).Value = infoClass.classId;
            sqlCmd.Parameters.Add("@className", SqlDbType.NVarChar).Value = infoClass.className;
            sqlCmd.Parameters.Add("@noOfseats", SqlDbType.Int).Value = infoClass.noOfSeats;
            int incount = sqlCmd.ExecuteNonQuery();
            if (incount > 0)
            {
                HttpContext.Current.Response.Write("<script>alert('Updated Successfully');</script>");
            }
        }
        catch (Exception )
        {
            throw;
        }
        finally
        {
            sqlCon.Close();
        }
    }

I want your help from here.

I sets btnSave.Text="Update" when press edit link button in gridview

 please send me the  btn_Click function to update