Dialog lookup method

public void fld1_1_lookup(FormControl _formControl, Name _ReportName)
{
    Query                   query   = new Query();
    QueryBuildDataSource    queryBuildDataSource;
    SysTableLookup          sysTableLookup;
    FormStringControl       _control = dialog.formRun().controlCallingMethod();//This is very important
    ;

    _formControl = _control;
    sysTableLookup = SysTableLookup::newParameters(tablenum(QVS_ReportName), _formControl);

    sysTableLookup.addLookupfield(fieldnum(QVS_ReportName, ReportId));
    sysTableLookup.addLookupfield(fieldnum(QVS_ReportName, ReportName), true);

    queryBuildDataSource = query.addDataSource(tablenum(QVS_ReportName));
    if(_ReportName)
        queryBuildDataSource.addRange(fieldnum(QVS_ReportName, ReportName)).value(strfmt("*%1*", _ReportName));

    sysTableLookup.parmQuery(query);
    sysTableLookup.performFormLookup();
}