/// <summary>
        /// This grid event perform 'Update User' operation.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void UserList_CellClick(object sender, DataGridViewCellEventArgs e)
        {
            try
            {
                if (e.RowIndex != -1 && e.ColumnIndex == UserList.Columns["colEdit"].Index)
                {
                    string userPrincipalName = UserList[UserList.Columns["colUserPrincipalName"].Index, e.RowIndex].Value.ToString();

                    // Opens 'Update User' page as a model dialog.
                    UserOperations userOperations = new UserOperations(UserOperations.UserOpertaionType.Update, userPrincipalName);

                    if (userOperations.ShowDialog() == DialogResult.OK) // If user updated successfully.
                    {
                        Cursor.Current = Cursors.WaitCursor;

                        // Update user list with updated user details.
                        Collection <PSObject> results = ExcutePowershellCommands();

                        if (results != null && results.Count > 0)
                        {
                            FillUserList(results);
                        }

                        Cursor.Current = Cursors.Default;
                    }
                }
            }
            catch (Exception ex)
            {
                Cursor.Current = Cursors.Default;
                MessageBox.Show(ex.Message);
            }
        }
        private void AddUser_Click(object sender, EventArgs e)
        {
            try
            {
                // Opens 'Add User' page as a model dialog.
                UserOperations userOperations = new UserOperations(UserOperations.UserOpertaionType.Save);

                if (userOperations.ShowDialog() == DialogResult.OK) // If user added successfully.
                {
                    Cursor.Current = Cursors.WaitCursor;
                    // Update user list with newly added user.

                    Collection <PSObject> results = ExcutePowershellCommands();

                    if (results != null && results.Count > 0)
                    {
                        FillUserList(results);
                    }

                    Cursor.Current = Cursors.Default;
                }
            }
            catch (Exception ex)
            {
                Cursor.Current = Cursors.Default;
                MessageBox.Show(ex.Message);
            }
        }