Aashish,
I see You use VFP 8. In this version GetDir() has a new parameter named nFlags:
GETDIR([cDirectory [, cText [, cCaption [, nFlags [, lRootOnly]]]]])
Check it in Help

nFlag Value Description 
1 BIF_RETURNONLYFSDIRS Return only file system directories (physical locations). If a user selects folders that are not part                 of the file system, the OK button is grayed.  
2 BIF_DONTGOBELOWDOMAIN Do not include network folders below the domain level in the tree view control (For example, My Computer and My Networks).  
8 BIF_RETURNFSANCESTORS Return only file system ancestors.
                        If a user selects anything other than a file system ancestor, the OK button is grayed.  
16 BIF_EDITBOX          The browse dialog includes an edit control in which the user can type the name of an item.
                        Available on Windows 98 and above, or with Internet Explorer 4.0 or higher (assuming shell
                        integration option selected). Requires version 4.71 of shell32.dll. 
32 BIF_VALIDATE         Validates the editbox contents. If the editbox is used, it is necessary to validate the
                        user-specified content. If the user types an invalid name into the edit box, the Cancel button
                        becomes the only selection available. This flag is ignored if BIF_EDITBOX is not specified. 
64 BIF_NEWDIALOGSTYLE   Use the new user-interface. Setting this flag provides the user with a larger, resizable dialog box.
                        Additional functionality includes: drag and drop capability within the dialog box, reordering, 
                        context menus, new folders, delete, and other context menu commands. Support in Windows 2000 and
                        above. Requires version 5.00 of shell32.dll. 
16384 BIF_BROWSEINCLUDEFILES The browse dialog will display files as well as folders.
                             Available on Windows 98 and above, or with Internet Explorer 4.0 or higher (assuming shell 
                             integration option selected). Requires version 4.71 of shell32.dll.