Bitcoin deposit verification

[Bitcoins4FF]

If I am running a tournament, how do I verify that a participant has deposited their entrance fee so that I can give them access to the tournament.

[BetWithCoins]

Im going to go out on a limb, and assume you mean a poker tourney? 

Create a new address per entrant. 
Record that address against your runner. 
Check the balance off that address via your wallet, blockchain.info etc.

Happy Punting!
www.betwithcoins.com

[micr0a]

you can use some lazy apis or daemon (bitcoind)

[Bitcoins4FF]

I'm sorry I was not specific enough in my original post.
This is not a commercial site, we are only having a March Madness
tournament Brackets.
I have been searching for an API, but have had no luck.
I have been searching websites that use bitcoins, but cannot seem to find any way to verify.
Thanks for your help.

[DannyHamilton]

I'm sorry I was not specific enough in my original post.
This is not a commercial site, we are only having a March Madness
tournament Brackets.
I have been searching for an API, but have had no luck.
I have been searching websites that use bitcoins, but cannot seem to find any way to verify.
Thanks for your help.

As has already been stated:

Create a separate address in your wallet for each participant.
Provide each participant with only the address you created for them.
When a deposit is made to the address, you know that participant has paid.