用js做延时提示框

效果预览：http://js.jirengu.com/dunakamini

思想

1. 首先是做出移入小div就显示大div，移出就隐藏
2. 之后解决从小的div移动到大div，还保持大div显示

  odiv1.onmouseout = function(){
    timer = setTimeout(function(){
      odiv2.style.display = 'none'
    },500) 
  }
  odiv2.onmouseover = function(){
    clearTimeout(timer)
  }

3. 再解决大div移动回小的div时的闪烁的问题

  odiv2.onmouseout = function(){
    timer = setTimeout(function(){
      odiv2.style.display = 'none'    //给移出大div时加入一个延时器，然后又要给小div的移入记得清除这一次的延时器，才能保持显示大div
    },500)
  }

4. 再合并相似的代码

  odiv2.onmouseover = odiv1.onmouseover = function(){
    clearTimeout(timer)
    odiv2.style.display='block'
  }
  odiv2.onmouseout = odiv1.onmouseout = function(){
    timer = setTimeout(function(){
      odiv2.style.display = 'none'
    },500) 
  }