diff --git a/src/MyFirstUDRKit.cpp b/src/MyFirstUDRKit.cpp
index be23ae5..72a8686 100644
--- a/src/MyFirstUDRKit.cpp
+++ b/src/MyFirstUDRKit.cpp
@@ -30,7 +30,7 @@
 #include <ibase.h>
 #include <firebird/UdrCppEngine.h>
 
-#include <assert.h>
+#include <cassert>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -85,11 +85,29 @@ FB_UDR_BEGIN_FUNCTION(MFK_flagged)
 
 	FB_UDR_EXECUTE_FUNCTION
 	{
-  if ( flags == NULL ) {
-    return 0;
-  }
-  ISC_UINT64 i = ( 1ULL << *flag );
-  return ( *flags & i ) ? 1 : 0;
+// Original code
+//  if ( flags == NULL ) {
+//    return 0;
+//  }
+		if ( in->flagsNull ) {
+			out->resultNull = FB_TRUE;
+			out->result = 0;
+		}
+		else
+		{
+			out->resultNull = FB_FALSE;
+// Original code
+//		ISC_UINT64 i = ( 1ULL << *flag );
+//		return ( *flags & i ) ? 1 : 0;
+			ISC_UINT64 i = ( 1ULL << in->flag );
+			out->result = ( in->flags & i ) ? 1 : 0;
+		}
 	}
 FB_UDR_END_FUNCTION
 
+
+
+
+
+
+