private void btnSave_Click(object sender, EventArgs e) { GroupModel objStudent = new GroupModel(); if (txtGroupNO.Text.ToString() != "") { objStudent.GroupNo = int.Parse(txtGroupNO.Text.ToString()); } else { objStudent.GroupNo = 0; } objStudent.Year = ddlYear.SelectedValue.ToString(); objStudent.Semester = ddlSem.SelectedValue.ToString(); objStudent.Program = ddlProgram.SelectedValue.ToString(); objStudent.GrouID = objStudent.Year + "." + objStudent.Semester + "." + objStudent.Program + "." + objStudent.GroupNo.ToString(); objCore.insertGroup(objStudent); //reset feilds txtGroupNO.Text = ""; loadData(); }