What is the API to get Bitcoin's real-time Buy price and sell price on my site? and how can get it from to implement in my website developed in PHP.

I tried with "*" but get error, and when tried with empty string then its returns only no label addresses instead of all addresses.
So, here account name is the address Label?

Thanks for your Reply!

But how can get account name? because in some functions its a mandatory parameter.
As well as how can create new account to assign Bitcoin addresses?
   

I have setup the BIK_php API of  http://bitcoindevkit.com/  in PHP.
Now, I am able to connect and generate new addresses, but when I am going to call some functions like getaddressesbyaccount, sendfrom etc as given in Bitcoin API call list at https://en.bitcoin.it/wiki/Original_Bitcoin_client/API_Calls_list , these functions requires "account" parameter as <account>, but I could not understand where from I can get the account value?
So, Please let me know what will be the value of <account>, and how can I get the <account>  value from?

I am going to develop an exchange website in PHP something like http://coinbase.com, Now, I have setup the http://bitcoindevkit.com/ for it and its running fine generating new addresses in the same wallet, but now I need to create a individual wallet for each user, so how can create individual wallet for each user and then I can able to create address on that wallet.

I am trying to create a website in PHP like http://www.coinbase.com where user can buy or sell bitcoins. So very first step in this is to allow users to create wallet.

Thanks for your reply. Is there any sample code available for this OR from where I can get some information on bitcoind via json?

I am trying to create a wallet for bitcoin using PHP. Can anyone let me know the steps to create wallet using PHP Code?