select组合框option的捕捉实例代码

<p>
<label class="title">报名参加的兼职职位(必填项)<br/>按住Ctrl键可多选</label>
<select onchange="showEasyVisitBox(this)" size="10" style="width: 200px;" multiple="multiple" id="kc_selectjob" name="kc_selectjob">
<option selected="selected" value="入户访问员">入户访问员</option>
<option value="街访访问员">街访访问员</option>
<option value="街访拦截员">街访拦截员</option>
<option value="电话访问员">电话访问员</option>
<option value="神秘顾客">神秘顾客</option>
<option value="专业人士访问员">专业人士访问员</option>
<option value="企业深访员">企业深访员</option>
<option value="定性联络员">定性联络员</option>
<option value="主持人">主持人</option>
<option value="质量控制员">质量控制员</option>
<option value="数据录入员">数据录入员</option>
</select>
</p>
<p id="supportvisitBox" style="display: none;">
<label class="title">可提供被访者类型</label>
</p>
<p id="easyvisitBox" style="display: none;">
<label class="title">容易接触到的行业</label>
</p>

var oListBox = document.getElementById("kc_selectjob");

oListBox.onchange = function showEasyVisitBox(){
var oEasyvisitBox = document.getElementById("easyvisitBox");
var oSupportvisitBox = document.getElementById("supportvisitBox");
if (oListBox.options[5].selected)
{
oEasyvisitBox.style.display = "block";
}
else {
oEasyvisitBox.style.display = "none";
}

if (oListBox.options[7].selected)
{
oSupportvisitBox.style.display = "block";
}
else {
oSupportvisitBox.style.display = "none";
}

}