Simple Form Not Submitting Post Values - forms

Question

I saw two other questions here with similar problems but neither answered the question that helps make this one work and the form itself is so basic that I can't imagine why it's not working. As you can see, it is a simple self-submitting select box. One of the other questions indicated that having name= and the label having a matching for= was the answer but this has those things already so no help there.
In fact, this form is generated dynamically (this is one of the simplest versions of it) and has been online and working for years so I am mystified about why it suddenly posts nothing! It causes the form to reload when a different selection is made but does not provide the ID value or any other post values. Anyone see something I missed or did the basics of forms somehow change?
<form id="Search" method="post" name="search" action="/admin/adminform.php">
<fieldset>
<legend>Select Entry</legend>
<p><label for="ID">Select</label>
<select name="ID" id="ID" onchange="this.form.submit()">
<option value=""></option>
<option value="4">Entry 4</option>
<option value="2">Entry 2</option>
<option value="1">Entry 1</option>
<option value="8">Entry 8</option>
<option value="6">Entry 6</option>
<option value="9">Entry 9</option>
<option value="5">Entry 5</option>
<option value="3">Entry 3</option>
</select>
<noscript>
<input type="submit" value="Get Selected Entry" name="Search">
</noscript>
</fieldset>
</form>

Answer 1

I looked at this all day without any success but then as soon as I posted the question as a last resort, I found the problem which was nothing to do with the form. There was another function being called that tests for whether or not JavaScript is enabled which does so by submitting a post that was apparently overpowering this one. Simply putting a conditional around it so that it runs only once fixed the form in question! For reference, here is the function causing the problem and the outer-most conditional sorted it out.
function IsJavaScript() {
if (!isset($_SESSION['JSEnabled'])) :
if (isset($_POST['jstest'])) :
return TRUE;
else :
echo '<form name="jsform" id="jsform" method="post" style="display:none">';
echo '<input name="jstest" type="text" value="true" />';
echo '<script language="javascript">';
echo 'document.jsform.submit();';
echo '</script>';
echo '</form>';
return FALSE;
endif;
endif;
}