BTC-E Trade Script Simple

<?php
function btce_query($method, array $req = array()) {
        // API settings
        $key = ''; // your API-key
        $secret = ''; // your Secret-key

        $req['method'] = $method;
        $mt = explode(' ', microtime());
        $req['nonce'] = $mt[1];

        // generate the POST data string
        $post_data = http_build_query($req, '', '&');

        $sign = hash_hmac("sha512", $post_data, $secret);

        // generate the extra headers
        $headers = array(
                'Sign: '.$sign,
                'Key: '.$key,
        );

        // our curl handle (initialize if required)
        static $ch = null;
        if (is_null($ch)) {
                $ch = curl_init();
                curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
                curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; BTCE PHP client; '.php_uname('s').'; PHP/'.phpversion().')');
        }
        curl_setopt($ch, CURLOPT_URL, 'https://btc-e.com/tapi/');
        curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);

        // run the query
        $res = curl_exec($ch);
        if ($res === false) throw new Exception('Could not get reply: '.curl_error($ch));
        $dec = json_decode($res, true);
        if (!$dec) throw new Exception('Invalid data received, please make sure connection is working and requested API exists');
        return $dec;
}


$result = btce_query("getInfo");


echo "Bitcoins:";
echo "\n";
echo "".print_r($result['return']['funds']['btc'])."";
echo "\n";
echo "USD:";
echo "\n";
echo "".print_r($result['return']['funds']['usd'])."";
echo "\n";

echo "High: $high";
echo "\n";

echo "Low: $low";
echo "\n";

echo "Last: $last";
echo "\n";

if ($result['return']['funds']['btc'] > .1)
{
$sell = btce_query("Trade", array("pair" => "btc_usd", "type" => "sell", "amount" => .998, "rate" => "Price you want to sell at.)); //sell 1 BTC @ $1 less than high.
echo "<pre>".print_r($sell, true)."</pre>";
}
else
{
        echo "No Bitcoins to trade at this time.";
}

echo "\n";

if ($result['return']['funds']['usd'] > .1 * $last)
{
$buy = btce_query("Trade", array("pair" => "btc_usd", "type" => "buy", "amount" => 1, "rate" => "Price you want to buy at.)); //buy 1 BTC @ $3 less than high.
echo "<pre>".print_r($buy, true)."</pre>";
}
else
{
        echo "No USD to trade at this time.";
}

echo "\n";

$orders = btce_query("OrderList");
echo "".print_r($orders['return'], 1)."";


?>