function callInProgress(xmlhttp)
{
	switch(xmlhttp.readyState)
	{
		case 1: case 2: case 3:
			return true;
			break;
		// Case 4 and 0
		default:
			return false;
			break;
	}
}

// Register global responders that will occur on all AJAX requests
Ajax.Responders.register(
{
	onCreate: function(request){
		request['timeoutId'] = window.setTimeout(
			function(){
				// If we have hit the timeout and the AJAX request is active,
				// abort it and let the user know
				if(callInProgress(request.transport))
				{
					request.transport.abort();
	
					// Run the onFailure method if we set one up
					// when creating the AJAX object
					if(request.options['onFailure'])
						request.options['onFailure'](request.transport, request.json);
				}
			},
			30 * 1000 // 30 seconds
		);
	},

	onComplete: function(request){
		// Clear the timeout, the request completed ok
		window.clearTimeout(request['timeoutId']);
	}
});