private void btnRemove_Click(object sender, System.EventArgs e) { //Confirm string text = AMResources.GetLocalizedString("ConfirmRemoveCourse"); DialogResult result = MessageBox.Show(text, "", MessageBoxButtons.YesNo, MessageBoxIcon.Question); if (result == DialogResult.Yes) { int nCount = deleteCourseList.Items.Count; ClientTools clientTools = new ClientTools(m_applicationObject); for (int i = 0; i < nCount; i++) { if (deleteCourseList.GetSelected(i)) { string courseGuid = courseGuids[i]; if (courseGuid != null && courseGuid != String.Empty) { clientTools.UnregisterAssignmentManagerCourse(courseGuid); } } } this.Close(); } }