create lookup runtime in axapta form

This is a sample code to create lookup runtime in axapta form

 public void lookup()  
 {  
 SysTableLookup tableLookup;  
 QueryBuildDataSource qbds, qbds1;  
 QueryBuildLink QueryBuildLink1;  
 Query q = new Query();  
 ;  
 tableLookup = SysTableLookup::newParameters(tableNum(_Taluka),this);  
 qbds = q.addDataSource(tablenum(_Taluka));  
 qbds.addRange(fieldnum(_Taluka, _DistrictCd)).value(District.valueStr());  
 tableLookup.parmQuery(q);  
 tableLookup.addLookupfield(fieldNum(_Taluka,_TalukaCd));  
 tableLookup.addLookupfield(fieldNum(_Taluka, _TalukaName));  
 tableLookup.performFormLookup();  
 }