JS setInterval executes only once
<p>I have the following JS functions:</p>

<pre><code>function checkIfGameAlreadyStarted(){
    $.get("IsGameAlreadyStarted",null,function(gameAlreadyStarted){
        if (gameAlreadyStarted == "true"){
            window.location = "index.jsp?content=game";       
        } else{
            alert("bla");
        }  
    });
}

function joinGame(playerForm){
    $.get("GenerateClientID",null,function(clientID){         
        $.get("JoinGame",{
            "NAME" : playerForm.elements[0].value,
            "ID" : clientID
        }
        ,function(gameParam){

            $("#waitingContainer").append("You have joined the game!&lt;br\&gt;Waiting for game creator to start game..");
            setInterval(checkIfGameAlreadyStarted(), 1000);    

        });
    });
}
</code></pre>

<p>Why does <code>setInterval</code> executes <code>checkIfGameAlreadyStarted</code> only once, and not every second?</p>
