Troubleshoot Request of my If then else VBScript Label Expression?

Hi,
I get an error message 'No features found. Could not verify expression.' when I try to verify the following VBScript label expression in 10.0 for a Shapefile Feature Class attribute table:

Function FindLabel ([HELTYPECD])
if ([HELTYPECD] = H) then FindLabel = ["HEL"] if ([HELTYPECD] = N) then FindLabel = ["NHEL"] if ([HELTYPECD] = NULL) then FindLabel = ["UHEL"]
end if End Function

To he/she who can fix it: Thank you!

Regards,
David