80分求助 如何改变默认的selected
<tr >
<td width="472" align=left><b>Have children?</b></td>
<td align=right id=s_h_t_match_have_children><A HREF="javascript:show_hide('match_have_children')">Hide</A></td>
</tr>
<tr id=s_h_match_have_children>
<td colspan=2 align='left'>
<select class=main_text_l name='match_have_children' onChange="replace_text();">
<option value='1'>No</option>
<option value='16'>No, but I want children</option>
<option value='32'>No, and I don't want children</option>
<option value='0'>No preference</option>
</select>
</td>
</tr>
JavaScript:
function show_hide(obj_name){
var obj = document.getElementById('s_h_'+obj_name);
var hideselect = document.getElementByName(obj_name);
if(obj.style.display=='') {
obj.style.display='none';
document.getElementById('s_h_t_'+obj_name).innerHTML="<A HREF=\"javascript:show_hide('"+obj_name+"')\">Show</A>";
for (var i=0; i < hideselect.obj_name.option.length; i++){
hideselect.obj_name.option[i].selected = false;
if (i == hideselect.obj_name.option.length - 1){
hideselect.obj_name.option[i].selected = true;
}
}
} else {
obj.style.display=''
document.getElementById('s_h_t_'+obj_name).innerHTML="<A HREF=\"javascript:show_hide('"+obj_name+"')\">Hide</A>";
}
}
在网页打开的时候 默认selected的是"No",我想在点击hide后 默认的selected不在是"No"而是"No Preference",请问JavaScript改怎么写呀 我上面自己写的不正确