Question about topping off chipstack - Foxwoods

[kurto]

Sorry... couldn't find this on initial search. I'm sure this is a basic question but I'm clueless.

I'll be playing for first B&M NL cash game at Foxwoods. I found that there's a 300max buyin and to buy chips at the cage before sitting down. That's cool.

My question is... say I lose $50 and want to keep my stack full. Can I have more then a buyin and just keep adding to my stack every time it goes below the max with chips from my pocket or do I have to rebuy from the dealer (which is probably annoying if you keeping rebuying after every hand you lose)?

Thanks.