[Hekumok]

<form action = "topic?page=" onsubmit = "send(this);">
<select id = "select">
 <option value = "1" select>1</option>
 <option value = "2">2</option>
</select>
<input type = "submit" value = "GO">
</form>
<script>
function send(form) {
 form.action += document.getElementById("select").value ;
alert(form.action) ;
} ;
</script>