private void button2_Click(object sender, EventArgs e) { int numoflec = 0; int numoftut = 0; int quantity; // for try parse string nameCourse = tb_nameCoures.Text; int Department_choose; char Year; char Semester; while (true) { //--------Name course check if ((nameCourse == "") || (int.TryParse(nameCourse, out quantity))) { MessageBox.Show("You need input legal name course"); //empty textBox or not integer tb_nameCoures.Clear(); break; } if (courses_db.ExistsCourse(nameCourse)) { MessageBox.Show("The course already exists"); //empty textBox or not integer tb_nameCoures.Clear(); break; } //-------Department check switch (cb_department.SelectedIndex + 1) { case 1: Department_choose = 1; break; case 2: Department_choose = 2; break; case 3: Department_choose = 3; break; case 4: Department_choose = 4; break; case 5: Department_choose = 5; break; case 6: Department_choose = 6; break; case 7: Department_choose = 7; break; default: MessageBox.Show("You're need to choose department"); Department_choose = 0; break; } if (Department_choose == 0) //empty department { break; } //-------Year check if (rb_aYear.Checked) { Year = 'A'; } else if (rb_bYear.Checked) { Year = 'B'; } else if (rb_cYear.Checked) { Year = 'C'; } else if (rb_dYear.Checked) { Year = 'D'; } else { MessageBox.Show("You must choose a year"); break; } //--------Semester check if (rb_aSemester.Checked) { Semester = 'A'; } else if (rb_bSemester.Checked) { Semester = 'B'; } else if (rb_cSemester.Checked) { Semester = 'C'; } else { MessageBox.Show("You must choose a semester"); break; } //--------Number houre of lectures check switch (cb_lec.SelectedIndex + 1) { case 1: numoflec = 1; break; case 2: numoflec = 2; break; case 3: numoflec = 3; break; case 4: numoflec = 4; break; default: MessageBox.Show("You're need to choose number of hours lectures"); numoflec = 0; break; } if (Department_choose == 0) //empty number of hours lectures { break; } //--------Number houre of tutores check switch (cb_tirgul.SelectedIndex + 1) { case 1: numoftut = 1; break; case 2: numoftut = 2; break; case 3: numoftut = 3; break; case 4: numoftut = 4; break; default: MessageBox.Show("You're need to choose number of hours tutores"); numoftut = 0; break; } if (numoftut == 0) //empty number of hours tutores { break; } //-------All detailse fine------ courses_db.insertCourses(nameCourse, Department_choose, Year, Semester, numoflec, numoftut); this.Hide(); break; } }