Buying a house using HELOC? Timing?

[Larry Miller]

I am looking at using a Home Equity Line Of Credit (HELOC) to buy a house in San Antonio but I am new and don't know how the timing will work. I know you can get pre-approved for a typical mortgage and use that pre-approval with your offer, but is there any way of showing funds available using a HELOC without actually borrowing the money. I don't want to borrow the money and have to make payments if the offer I make falls through. On the other hand, the bank I talked to said it will take 30 to 45 days for the HELOC to be processed.

I guess my question is: How do you work the timing when using a HELOC to buy a cash house?