javascript - 从选定的选项中获取文本

Question

当用户输入他们的地址详细信息时，我正在收集数据并创建一行来显示。我可以使用这样的行设置文本输入 var address1 = document.address.address1.value; ，但城镇是一个选择框，其值是 ID，文本是我需要的值去收集。对于文本输入，我使用 onkeyup="autoAddress();" ，对于选择，我使用 onchange="autoAddress();"。

行 vartown = document.address.town_id.value 返回我的 ID，但我需要文本:

<input type="text" name="address1" id="address1" data-rule-required="true" class="form-control" value="{$form_data.address1}" onkeyup="autoAddress();">
<input type="text" name="address2" id="address2" class="form-control" value="{$form_data.address2}" onkeyup="autoAddress();">
<select class="form-control chosen" name="town_id" id="town_id" data-rule-required="true" data-placeholder="Choose a town" onchange="autoAddress();">
    <option value=""></option>
    {foreach $towns as $town}
    <option value="{$town.id}" {if $town.id eq $form_data.town_id}selected="selected"{/if}>{$town.town_name} {if $town.region_name}, {$town.region_name}{/if}</option>
    {/foreach}
</select>

function autoAddress(){
    var house_number = document.address.house_number.value;
    var address1 = document.address.address1.value;
    var address2 = document.address.address2.value;
    var town = document.address.town_id.value;
    var postcode = document.address.postcode.value;
}

Answer 1

var town = document.address.town_id.options[document.address.town_id.selectedIndex].innerHTML;