[Dilettante_Pro]

<script src="https://code.jquery.com/jquery-latest.min.js"></script>
<script>
$(document).ready(InitPage);
function InitPage() {
   var inputs={};
   $('#testform select').each(function(){
      getQuery(this);
   });
   $('#testform select').on('change',function(){
      getQuery(this);
   });
   $('#show').on('click',function(){
      var action=$('#testform').attr('action');
      action+=$.param(inputs)?'?'+$.param(inputs):'';
      alert(action);
   });
   function getQuery(el){
       if($(el).val()!=''){
           inputs[$(el).attr('name')]=$(el).val();
       }else{
           delete inputs[$(el).attr('name')];
       }
   }
}
</script>
<form id="testform" action="get.php" method="GET">
    <select name="sel1" >
        <option value="">Выберите</option>
        <option value="1">Пиво</option>
        <option value="2">Спирт</option>
        <option value="3">Лимонад</option>
    </select>
    <select name="sel2" >
        <option value="">Выберите</option>
        <option selected value="3">Колбаска</option>
        <option value="4">Мясо</option>
		<option value="5">Деньги</option>
    </select>  
</form>
<input id="show" type="button" value="Показать"/>