window.onload=function(){
	var error = false;
	var lastEvent  = new Date().getTime();
	function internKeepalive() {
    	var now = new Date().getTime();
    	/* Terminate if error occurred on keepalive */
    	if (error)
    		return;
    	/* Start after a minute to send keepalives */
    	if ((now - lastEvent) > 60000) {
    		var options = {
				'url' : '/visionr.vsp?ajax=true&operation=keepalive&' + _PARAMS,
				'onSuccess': function(data){ eval(data); },
				'onError': function(data) { error=true; }
    		};
    		jx.bind(options);
    	}
    	window.setTimeout(internKeepalive, 120000);
	}
	window.setTimeout(internKeepalive, 120000); 
}
