Save function-value

Hi

I've got at simple problem. I've got at function called "driftsomkostninger" (and it's a function of p and q). In one of my scripts I need the value of driftsomkostninger(78,0). So I tried writing:

min_omk=driftsomkostninger(78,0)

But this gives me "too many output arguments". I've tried to read something about exactly this. But it didn't quite help. Have any of you got an idea ?