JavaScript如何从listbox里同时删除多个项目

<table>
<tr>
<td align="center">
<select id="lsbox" name="lsbox" size="10" multiple>
<option value="1">India</option>
<option value="2">United States</option>
<option value="3">China</option>
<option value="4">Italy</option>
<option value="5">Germany</option>
<option value="6">Canada</option>
<option value="7">France</option>
<option value="8">United Kingdom</option>
</select>
</td>
</tr>
<tr>
<td align="center">
<button onclick="listbox_remove('lsbox');">Delete</button>
<button onclick="window.location.reload();">Reset</button>
</td>
</tr>
</table>

function listbox_remove(sourceID) {
//get the listbox object from id.
var src = document.getElementById(sourceID);

//iterate through each option of the listbox
for(var count= src.options.length-1; count >= 0; count--) {

//if the option is selected, delete the option
if(src.options[count].selected == true) {

try {
src.remove(count, null);

} catch(error) {

src.remove(count);
}
}
}
}

$("#sourceId").find('option:selected').remove();