Add sample code for warningif opcode.

Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14789 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/DriverSampleDxe/Vfr.vfr

@@ -259,6 +259,9 @@ formset
       help        = STRING_TOKEN(STR_ONE_OF_HELP),
       option text = STRING_TOKEN(STR_ONE_OF_TEXT1), value = 0, flags = RESET_REQUIRED;
       option text = STRING_TOKEN(STR_ONE_OF_TEXT2), value = 1, flags = DEFAULT | RESET_REQUIRED;
+      warningif prompt = STRING_TOKEN(STR_WARNING_POPUP), timeout = 5,
+        ideqval MyIfrNVData.TestLateCheck == 0
+      endif
 
     endoneof;