I'll echo Bruce. If you must check all four variables for nulls, there is no getting around just doing it. But maybe if you'll tell us the WHY behind it, someone might have some ideas about alternatives. The only clue we have right now is that you are appearing to be setting up some kind of a search. Can you give us the bigger picture, please?
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Against stupidity the gods themselves contend in vain. -- Friedrich Schiller
Stop, children, what's that sound? Everybody look what's going down. -- Stephen Stills