protected void Button2_Click(object sender, EventArgs e)
    {
      this.lblMessage.Text = "";

      string mId = string.Empty;


      for (int i = 0; i <= gvUserList.Rows.Count - 1; i++)
      {
        CheckBox cb1 = (CheckBox)gvUserList.Rows[i].FindControl("cb1");
        if (cb1.Checked)
        {
          mId = mId + gvUserList.DataKeys[i].Value + ",";
        }
      }

      mId = mId.Substring(0, mId.Length - 1);
      Business.UserComponent uc = new UserComponent();
      uc.DeleteUser(mId);
      getUsers();
    }