Greetings

I've implemented the live agent functionality, and i made every step described in the documentation, but, no matter what i do, the chat always is offline, even if i have two service cloud users  online in the console. 

This is the VF code:

<apex:page >    
    <h1>Welcome</h1>
       

        <!-- START Button code -->      
            <img id="liveagent_button_online_573i00000001vzN" style="display: none; border: 0px none; cursor: pointer" onclick="liveagent.startChat('573i00000001vzN')" src="https://xxdemo.force.com/contacto/resource/1378315436000/online" /><img id="liveagent_button_offline_573i00000001vzN" style="display: none; border: 0px none; " src="https://xxdemo.force.com/contacto/resource/1378315454000/offline" />
<script type="text/javascript">
if (!window._laq) { window._laq = []; }
window._laq.push(function(){liveagent.showWhenOnline('573i00000001vzN', document.getElementById('liveagent_button_online_573i00000001vzN'));
liveagent.showWhenOffline('573i00000001vzN', document.getElementById('liveagent_button_offline_573i00000001vzN'));
});</script>

        <!-- END Button code -->

        <!-- Deployment code --> 
<script type='text/javascript' src='https://c.la2c1.salesforceliveagent.com/content/g/deployment.js'></script>
<script type='text/javascript'>
liveagent.init('https://d.la2c1.salesforceliveagent.com/chat', '572i00000001txY', '00Di0000000eFdt');
</script>
</apex:page>

What i am doing wrong?