<html>
<body>
<script language="javascript">
function getSelectedText(name){
var obj =document.getElementById(name);
for(i=0;i<obj.length;i++)
  {
    if(obj[i].selected==true)
      {
        return obj[i].innerText;
      }
  }

}
</script>
<select id="myselect">
<option value="1">中国</option>
<option value="1">美国</option>
<option value="1">英国</option>
</select>
<input type="button" value="所选文本" onclick="alert(getSelectedText('myselect'))"/>