LoadBlobFromFile takes only a single parameter and returns a blob

sql/MyFirstUDRKit.ddl

@@ -19,9 +19,8 @@ grant execute on function flagged to public;
 
 
 create or alter function LoadBlobFromFile (
-	afilename varchar(8191),
-	ablob BLOB
-	) returns bigint
+	afilename varchar(8191)
+	) returns BLOB
 	external name 'MyFirstUDRKit!MFK_LoadBlobFromFile!Load file and save to Blob'
 	engine udr;
 grant execute on function LoadBlobFromFile to public;

src/MyFirstUDRKit.cpp

@@ -174,11 +174,10 @@ FB_UDR_BEGIN_FUNCTION (MFK_LoadBlobFromFile)
 //BEGIN
 FB_UDR_MESSAGE(InMessage,
 							 (FB_VARCHAR(8191), afilename)
-							 (FB_BLOB, ablob)
 );
 
 FB_UDR_MESSAGE(OutMessage,
-							 (FB_BIGINT, result)
+							 (FB_BLOB, ablob)
 );
 
 
@@ -190,8 +189,8 @@ FB_UDR_EXECUTE_FUNCTION
 {
 	// Test Input
 	if (in->afilenameNull != 0)  {
-		out->resultNull = FB_TRUE;
-		out->result = 0;
+		out->ablobNull = FB_TRUE;
+		return;
 	}
 
 	std::ifstream FileReader;