Gwirio a yw enwau' r newidynnau amgylchedd a roddwyd yn ddilys. Os na chanfyddir newidyn amgylchedd, fe amlygir y labeli cysylltiedig i ddangos y gosodiadau annilys.
Verify whether or not the environment variable names you supplied are valid. If an environment variable is not found, the associated labels will be highlighted to indicate that they are invalid.