js中 select 选项点击改变 div中的值

window.onload=function(){

var selectid= document.getElementById("selectedid");

var index=selectid.selectedIndex;

var Text=selectid.options[index].text;

var divid=document.getElementById("divid");

divid.innerHTML=Text;

}

<select id="selectid">

<option value="beijng">北京<option>

<option value="tianjin">天津<option>

<option value="shanghai">上海<option>

</select>

<div id="divid>

</div>