Pre-Lease Office Space before purchase?

[Paul C.]

Is it legal to, and how can you pre-lease office space before you close or even offer to buy an office space?

It seems that I have found what looks like a great deal on a small office building but would need help raising all the down payment money. Is it possible to find potential tenants and sign a long term lease contengent on my closing the deal? My strategy would be to use deposit money to make up the difference I'm lacking.