2015.08.11-背景颜色切换函数

<div> class=‘red‘ id="box">美美哒！...........</div>

.red{
   width:100px;
   height:100px;
   background-color:red;
   border-radius:0 70px 0 60px ;
   transition-duration:1s;
}
.yellow{
 width:150px;
 height:150px;
 border-radius:80px 0 100px 0;
 transition-duration:1s;
 background-color:yellow;
}

window.onload = function(){
  var box = document.getElementById(‘box‘);
  box.onclick = toYellow;
};

function toRed(){
   this.className =‘red‘;
   this.onclick = toYellow;
}

function toYellow(){
  this.className =‘yellow‘;
  this.onclick = toRed;
}