Как получить значения всех select в php массив?

var selectionCounter = 0 
    function cloneSelect() { 
        var select = document.getElementById("statement") 
        var clone = select.cloneNode(true) 
        var name = select.getAttribute("name") + selectionCounter++ 
        clone.id = name 
        clone.setAttribute("name", name) 
        document.getElementById("selectContainer").appendChild(clone) 
        
 
    }

<link href="http://maxcdn.bootstrapcdn.com/bootstrap/3.3.0/css/bootstrap.min.css" rel="stylesheet"/> 
<div class="col-md-8 inputGroupContainer"> 
  <div id="selectContainer" > 
    <select class="form-control" id="statement" name="statement"> 
     <option value="1">One</option> 
     <option value="2">Two</option> 
     <option value="3">Three</option> 
     <option value="4">Four</option> 
     </select> 
   </div>      
   <button onclick="cloneSelect()">Добавить продукт</button> 
</div> 
<div style="text-align: right"> 
<input type="submit" class="btn btn-group btn-success" value="Добавить" > 
<a href="suppliers.php" class="btn btn-group btn-danger">Отмена</a> 
                    </div>