DataSet dsClass=new DataSet();

DataTable dtClass=new DataTable("Class");

DataColumn id=new DataColumn("id",typeof(int));

DataColumn className=new DataColumn("className",typeof(string));

DataColumn gradeID=new DataColumn("gradeID",typeof(int));

dtClass.Columns.Add(id);

dtClass.Columns.Add(className);

dtClass.Columns.Add(gradeID); DataRow drClass=dtClass.NewRow();

drClass["className"]=this.txtClass.Text.Trim();

drClass["gradeID"]=gradeManager.GetGradeIDByGradeName(this.cboGrade.Text.Trim());

dtClass.Rows.Add(drClass);

dsClass.Tables.Add(dtClass);