js获得<select><option>的值跟文本

<SELECT id="s" onchange="pageChage()">

   <option value="0">0</option>

   <option value="1">5</option>

   <option value="2">10</option>

   <option value="3">15</option>

 </SELECT>

<script type="text/javascript">

function pageChage(){

var s = document.getElementById("s");
var value = document.getElementById("s").value;//0,1,2,3
var text = s.options[s.selectedIndex].text;//0,5,0,15

}

</script>