平成30/ 2018-12-19 17:43
javascript/ selectbox

<select id="item_note_li" onchange="
var obj = document.getElementById('item_note_li');
document.getElementById('item_note').value = obj.options[obj.selectedIndex].text;
">
<option></option>
<option>エスタックイブ</option>
</select>
<br />
<input type="text" name="item_note" id="item_note" style="width:100%" value="<?php echo h($li["item_note"]); ?>" />
</div>


( Thanks. )
Javascript Select 値
http://webcache.googleusercontent.com/search?q=cache:c3aNQa8eKroJ:blog.quall.net/program/225/+javascript+select+%E5%80%A4+getelementbyid&cd=1&hl=ja&ct=clnk&gl=jp&source=www.google.co.jp
function selectCheck() {
    var formElement1 = document.getElementById('formId1');
    var selElement1  = document.getElementById('selId1');
    alert(selElement1.selectedIndex);
    alert(selElement1.options[selElement1.selectedIndex].value);
    alert(selElement1.options[selElement1.selectedIndex].text);
    formElement1.submit();
}