I am developing a web application in PHP. I wish to be able to detect incoming transactions whenever they come, by using the 'listunspent' Bitcoin JSON RPC call. As expected, a long list of transactions are spewed out. My problem is that I don't see how I would be able to deal with each of the transactions in the array. I tried using this code to test with at first:

function processTransaction() {
    global $bitcoin;
    $unspent = $bitcoin->listunspent();
    $address = $unspent['address'];
    echo $address;
} 

However, as expected, the function does not work. I am guessing that I would have to loop through the entire 'unspent' array and deal with each transaction individually. This is where I get stuck. How do I select or loop through this entire array?

Also, once I have dealt with a transaction, is there a way to mark the transaction as 'spent'? Is there a way to do this without having to send the coins to another wallet?

The kind of code I think I would have to use is something similar to this:

function processTransaction() {
    global $bitcoin;
    $unspent = $bitcoin->listunspent();

        foreach ($unspent as $address) {
            //...do something with the address
            //...mark transaction as 'spent'
        }
}

(Just so that you are in context with the question, here is a brief overview of the site I am developing. The site is called 'Vertodds' and what it is, is a gambling site. You enter in your Vertcoin address and a new unique deposit address is created for you. You can then deposit VTC into your unique deposit address, and there is a 49% chance of doubling your coin.)

Thank you very much for your time and knowledge.