var blinken;
var timer = 750;
var zColor = 0;
var isOver = false;
var id = "b5";

function blink() {
 if (isOver == false && zColor % 2 == 0) {
  document.getElementById(id).style.backgroundColor = "#FFF";
  setTimeout("blink()",750);
  ;
 }
 else if (isOver == false && zColor % 2 != 0) {
  document.getElementById(id).style.backgroundColor = "#C0E0FF";
  setTimeout("blink()",3000);
 }
 zColor++;
}

function blinkOver() {
 document.getElementById(id).style.backgroundColor = "#FFE";
 isOver = true; 
}

function blinkOut() {
 document.getElementById(id).style.backgroundColor = "#C0E0FF";
 isOver = false;
}