Enum Based Listpage Filteration in Ax 2012

//List page filter-----------------------------------using Enum control
public boolean modified()
{
    StudentGender               studentgender;
    QueryBuildDataSource        qbds;
    QueryBuildRange             qbr;

    boolean ret;

    ret = super();

    qbds = stutable_1_ds.query().datasourcetable(tablenum(stutable));
    //qbr = qbds.addrange(fieldnum(stutable, studentgender));
    qbr = SysQuery::findOrCreateRange(qbds, fieldNum(StuTable, StudentGender));

    if (StudentGender::Male == str2enum(studentgender, studGender.valuestr()))//StudGender.selection())
    {
       qbr.value(queryValue(StudentGender::Male));

    }
    else if(StudentGender::Female == str2enum(studentgender, studGender.valuestr()))//StudGender.selection())
    {
       qbr.value(queryValue(StudentGender::Female));
    }
    else
    {
        info("gmd");
    }
     StuTable_1_ds.executeQuery();
     StuTable_1_ds.research();
   
    return ret;
}