GridView Events is not firing in ASP.NET

Sir, In my Web application , some GridView events is not firing.

They are:-

Row_Deleting()

Row_Updating()

Row_CancelingEdit()

Row_Editing()

Please go through the code I given below and find out where the mistake lies.

and here the html code of my application:-




onclick="btnSave_Click" />	onclick="btnClear_Click" />

BorderColor="#999999" BorderStyle="Solid" BorderWidth="1px" CellPadding="3"
ForeColor="Black" GridLines="Vertical"
onrowcancelingedit="gvClass_RowCancelingEdit" onrowcommand="gvClass_RowCommand"
onrowdeleting="gvClass_RowDeleting" onrowediting="gvClass_RowEditing"
onrowupdating="gvClass_RowUpdating" onselectedindexchanging="gvClass_SelectedIndexChanging"
>

<%#Container.DataItemIndex+1 %>

Edit

Delete

Update

Cancel

And the C# code to function the GridEvents :-

protected void gvClass_SelectedIndexChanging(object sender, GridViewSelectEventArgs e)
{
gvClass.PageIndex = e.NewSelectedIndex;
GridFill();
}

protected void gvClass_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
gvClass.EditIndex = -1;
GridFill();
}

protected void gvClass_RowCommand(object sender, GridViewCommandEventArgs e)
{

}
public void ClassDelete(string decClassId)
{
try
{
if (sqlCon.State == ConnectionState.Closed)
{
sqlCon.Open();
}
SqlCommand cmd = new SqlCommand("ClassDelete", sqlCon);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("@classId", SqlDbType.Decimal));
cmd.Parameters["@classId"].Value = Convert.ToInt32(decClassId.ToString());
SqlDataAdapter sqlDa = new SqlDataAdapter(cmd);
DataSet dSet = new DataSet();
sqlDa.Fill(dSet);
}
catch (Exception)
{

throw;
}
}
protected void gvClass_RowDeleting(object sender, GridViewDeleteEventArgs e)
{
Label lblCLASSID = (Label)gvClass.Rows[e.RowIndex].FindControl("lblClassId");
string CLASSID = lblCLASSID.Text;
classSP spClass = new classSP();
ClassDelete(CLASSID);
HttpContext.Current.Response.Write("");
gvClass.EditIndex = -1;
GridFill();

}

protected void gvClass_RowEditing(object sender, GridViewEditEventArgs e)
{
gvClass.EditIndex = e.NewEditIndex;
GridFill();
}
public void ClassUpdate(string CLASSID, string CLASSNAME, string NoOfSEATS)
{
try
{
if (sqlCon.State == ConnectionState.Closed)
{
sqlCon.Open();
}
SqlCommand cmd = new SqlCommand("ClassEdit", sqlCon);
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add(new SqlParameter("@classId", SqlDbType.Decimal));
cmd.Parameters.Add(new SqlParameter("@className", SqlDbType.VarChar));
cmd.Parameters.Add(new SqlParameter("@noOfSeats", SqlDbType.Int));
cmd.Parameters["@classId"].Value = Convert.ToDecimal(CLASSID.ToString());
cmd.Parameters["@className"].Value = CLASSNAME;
cmd.Parameters["@noOfSeats"].Value = Convert.ToInt32(NoOfSEATS.ToString());
SqlDataAdapter sqlda = new SqlDataAdapter(cmd);
DataSet dSet = new DataSet();
sqlda.Fill(dSet);

}
catch (Exception)
{

throw;
}
}
protected void gvClass_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
Label lblCLASSID = (Label)gvClass.Rows[e.RowIndex].FindControl("lblClassId");
TextBox txtCLASSNAME = (TextBox)gvClass.Rows[e.RowIndex].FindControl("txtClassName");
TextBox txtSeats = (TextBox)gvClass.Rows[e.RowIndex].FindControl("txtnoOfSeats");
string CLID = lblCLASSID.Text;
string CLName = txtCLASSNAME.Text;
string NoSeats = txtSeats.Text;
classSP spClass = new classSP();
ClassUpdate(CLID, CLName, NoSeats);
HttpContext.Current.Response.Write("");
gvClass.EditIndex = -1;
GridFill();
}