<form method="POST" action='new_page_name.php'>
<select name="q" onchange="submit()">
<option value="1">Choice #1</option>
<option value="2">Choice #2</option>
<option value="3">Choice #3</option>
</select>
</form>
http://www.w3schools.com/tags/tag_form.asp
http://www.google.bg/search?hl=bg&newwindow=1&safe=off&site=&source=hp&q=html+form