javascript获得下拉列表的值
<script>
function show(){
alert(document.myform.mysel.options[document.myform.mysel.selectedIndex].text);
}
</script>
<form name="myform">
<select name="mysel" onchange="show()">
<option value="1">上海</option>
<option value="2" selected="selected">天津</option>
<option value="3">北京</option>
</select>
</form>