Online Circular Chess in Silverlight, ASP.NET AJAX, WCF Web Services, and LINQ to SQL

/// <reference path="ChessBoard.aspx" />
/// <reference path="App_Script/HelperFunctions.js" />

function pageLoad() 
{
    UpdateUserActivity();
}

function UpdateUserActivity()
{
    var proxy = new CChessService.ICChessService();
    // Updates the last activity so you don't get offline
    proxy.UpdateUserActivity(UserActivityUpdated);
}

function UserActivityUpdated()
{
    // Delay the next update 20 seconds
    setTimeout("UpdateUserActivity()", 20000);
}