how can use this code in web

private void dataGridView1_CellEndEdit(object sender, DataGridViewCellEventArgs e)
       {
           switch (e.ColumnIndex)
           {
               case 0:
                   if (dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value != null)
                   {
                       string cat_id = dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString();
                       DataGridViewComboBoxCell dgvcc;
                       dgvcc =(DataGridViewComboBoxCell) dataGridView1.Rows[e.RowIndex].Cells[1];
                       dgvcc.DisplayMember = "item_name";
                       dgvcc.ValueMember = "item_id";
                       dgvcc.DataSource = DAL.item.view(cat_id);

                   }
                   break;
               case 1:
                   if (dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value != null)
                   {
                       DataGridViewComboBoxCell dgvcc;
                       dgvcc = (DataGridViewComboBoxCell)dataGridView1.Rows[e.RowIndex].Cells[1];
                       DataTable dt = (DataTable)dgvcc.DataSource;
                       string item_id = dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString();
                       DataRow[] dr = dt.Select("item_id=" + item_id);

                       dataGridView1.Rows[e.RowIndex].Cells[2].Value = dr[0]["rate"];
                       //MessageBox.Show(dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value.ToString());

                   }
                   break;
               case 3:
                   if (dataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value != null)
                   {
                       int rate = Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[2].Value);
                       int qty = Convert.ToInt32(dataGridView1.Rows[e.RowIndex].Cells[3].Value);
                       int total = rate * qty;
                       dataGridView1.Rows[e.RowIndex].Cells[4].Value = total;
                       gtotal += total;
                       lblTotal.Text = gtotal.ToString();
                   }
                   break;



           }
       }