var napTime = 0;
var isSleeping = false; //Hey, I'm not sleeping
var sleepTime = 2400;

function initSleepMode() {   
   if (typeof(jQuery) == "undefined") {
      setTimeout("initSleepMode();", 100); //Oops, no dinner yet
   } else {
      jQuery(function() {
         jQuery(document).ready(function() {
            setInterval("isNapping();", 1000); //Increase napping time
            jQuery("#divSleep").hide();
            jQuery(document).keypress(function(e) {
               napTime = 0;
               wakeUp();
            });
            jQuery(this).mousemove(function(e) {
               napTime = 0;
               wakeUp();
            });
         });
      });
   }
}

function isNapping() { //Keep my bed ready..
   napTime += 10;
   if(napTime > sleepTime) {
      sleepMode();
   }
}

function sleepMode() { //huh! I’m feelin sleepy
   if(!isSleeping) {
      jQuery("#divSleep").show().css({
         height: "0",
         width: "0",
         left: "10%",
         top: "10%"
         }).animate({
            width: "100%",
            height: jQuery(window).height(),
            left: "0",
            top: "0",
            opacity: "0.93"
         }, 1500);
      isSleeping = true;
   }
}

function wakeUp() { //Wake’up Time!
   if(isSleeping) {
      jQuery("#divSleep").animate({
         width: "0",
         height: "0",
         opacity: "0",
         left: "50%",
         top: "50%"
      }, 500);
      setTimeout('jQuery("#divSleep").hide();', 700);
      isSleeping = false;
   }
}