<form name="myForm">
<script>
function mysearch() {
var q1 = $("#mySelectId1 option:selected").text();
var q2 = $("#mySelectId2 option:selected").text();
document.location.href = "http://www.site.ru/search/?q=" + q1 + q2;
}
</script>

[b]Выберите год:[/b]
<select id="mySelectId1" name="mySelect1">
<option value="str0">1</option>
<option value="str1">2</option>
<option value="str2">3</option>
</select>

[b]Выберите номинал:[/b]
<select id="mySelectId2" name="mySelect2">
<option value="str0">a</option>
<option value="str1">b</option>
<option value="str2">c</option>
</select>

<input type="button" class="searchSbmFl" name="sfSbm" value="Найти" onclick="mysearch()"/>

</form>