How to add custom lookup in Dynamics AX 2012 Through X++

How to add custom lookup in Dynamics AX 2012 Through X++

public void lookup(FormControl _formControl, str _filterStr)

{

        //super(_formControl, _filterStr);

        Query                               query = new Query();

        QueryBuildDataSource    queryBuildDataSource;

        SysTableLookup               sysTableLookup;

    

        sysTableLookup          = SysTableLookup::newParameters(tableNum(TableName), _formControl);

        queryBuildDataSource    = query.addDataSource(tableNum(TableName));

        

        sysTableLookup.addLookupField(fieldNum(TableName, Field1));

        sysTableLookup.addLookupField(fieldNum(TableName, Field2));

        sysTableLookup.parmQuery(query);

        sysTableLookup.performFormLookup();

}