Filter by field and Filter by selection on a display method in AX 2009

This achievement is not my invention as followed from another blog. This was very good and worked for me. :)  
Requirement:Add options "Filter By Field", "Filter By Selection" and "Remove Filter" in a display field "Name".

Steps:
1. Make "Name" control as Auto declaration to YES
2. Override context method in the same control and paste the following code: This form is having data from Employee details.

public void context() {     int                     selectedMenu;     formrun                 SearchformRun;     Args                    arg;     Name                    strtext;     querybuilddataSource    querybuilddataSource;     queryrun                qr;     query                   q;     PopupMenu menu = new PopupMenu(element.hWnd());     int a = menu.insertItem('Filter By Field');     int b = menu.insertItem('Filter By Selection');     int c = menu.insertItem('Remove Filter');     ;     q   = EmplTable_ds.query();     querybuilddataSource = q.dataSourceTable(tablenum(EmplTable));     querybuilddataSource = querybuilddataSource.addDataSource(TableNum(DirPartyTable));     querybuilddataSource.addLink(FieldNum(EmplTable,PartyId),FieldNum(DirPartyTable,PartyId));     selectedMenu = menu.draw();     switch(selectedMenu)     {         case -1: //Filter by field             break;         case a:                 arg = new args('SysformSearch');                 SearchformRun = new formrun(arg);                 SearchformRun.run();                 SearchformRun.wait();                 //Reading User entered value for filter process                 strtext = SearchformRun.design().controlName('FindEdit').valueStr();                 if(strtext)                 {                 //Creating a query for filter                     querybuilddataSource.addRange(FieldNum(DirPartyTable,Name)).value(strtext);                     EmplTable_ds.query(Q);                     EmplTable_ds.executeQuery();                 }                 break;         case b:                                      // Filter By Selection                 querybuilddataSource.addRange(FieldNum(DirPartyTable,Name)).value(smylEmplName.valueStr());                     EmplTable_ds.query(Q);                     EmplTable_ds.executeQuery();                 break;         case c :                                      // Remove Filter                 q   = new Query();                 querybuilddataSource = q.addDataSource(tablenum(EmplTable));                 querybuilddataSource.clearLinks();                 querybuilddataSource.clearRanges();                 EmplTable_ds.query(Q);                 EmplTable_ds.removeFilter();                 break;         Default:                 break;     } }