Entrez Gene IDs

I am using a program requiring Entrez Gene IDs. How do I find those for large gene lists? WormMart does not provide that option to my knowledge.

You can get a rough mapping by using BioMart from the EnsEMBL website,
but as the NCBI gene models, EnsEMBL and WormBase are not always in sync,
some of them might be missing or out of date.

WormMart does not offer the option “Entrez ID” - I think this should be changed.
BioMart works, but is incomplete :-(.

Any other ideas?

I used BioMart from EnsEMBL to import the NCBI ids into WormBase,
so it is in the same state (as in WS190 for the WormBase ids and whatever release NCBI had at that time for their ids).

But I will build WS200 for EnsEMBL in March, which will also more or less sync the NCBI and EnsEMBL ids until either NCBI or we update gene models.