private void btnAdd_Click(object sender, EventArgs e) { try { var className = this.txtClassName.Text; //var teacher = this.cmbTeacher.ValueMember; var teacher = Convert.ToInt32(cmbTeacher.SelectedValue); var grade = this.cmbClassGrade.Text; var des = this.txtClassDes.Text; if (className == "" || grade == "") { MessageBox.Show("class name requied and grade is required "); } else { manageClassrooms myC = new manageClassrooms(); if (myC.setClass(className, grade, Convert.ToInt32(teacher), des) == true) { MessageBox.Show("Added Class Successfully", "System Notification", MessageBoxButtons.OK, MessageBoxIcon.Information); this.refresh(); } } } catch (Exception ex) { MessageBox.Show("Failed to add class" + ex, "Application Error", MessageBoxButtons.OK, MessageBoxIcon.Warning); } }