title: how to concate the jquery clone object to string
body: <p>i have select2 box cloned and now i want to concatenate the cloned object with string and then append it to target field.
  the html is </p>
  
  <pre><code>&lt;select data-placeholder="Select a billable item" name="nvoice_billable_ITEMID" id="invoice_billable_ITEMID" class="invoice_billable_ITEMID"&gt;
      &lt;option value=""&gt;&lt;/option&gt;
      &lt;option value="35089"&gt;Initial&lt;/option&gt;
      &lt;option value="35088"&gt;Standard&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>i use code to initialize the select js code. </p>
  
  <pre><code> var select_billable;
  $(document).ready(function() {
      select_billable = $('.invoice_billable_ITEMID').clone();
      $(".nvoice_billable_ITEMID").select2({
          allowClear: true
      });});
  </code></pre>
  
  <p>on the function call add_fields i create the clone object and after concatenating it with string append it to target element. the clone object is created well but after append the string is showing <code>[object Object]</code>in the place of cloned object with in sting . how can i concatenate the object with string so that the select box is visible ??</p>
  
  <pre><code>//on call add the field for item
  function add_fields(item_type){
      if(item_type == "Billable"){
          //   create the clone of select2 box
          var newBillableSelect = select_billable.clone();
          //function for concate the select2 box with string and append it
          appendRow(newBillableSelect);
          //initilizing the new select2 box
          newBillableSelect.select2();   
      }else if(item_type == "Product"){
          var newProductSelect = select_product.clone();
          appendRow(newProductSelect);
          newProductSelect.select2();  
      }
  }
  function appendRow(selectBox){
      var tr = '&lt;tr class="fields_group" id="fields_group_ITEMID"&gt;'+
          '&lt;td&gt;'+ selectBox.html() +'&lt;/td&gt;'+
          '&lt;td&gt;$&lt;input type="text" style="width: 60px" size="30" name="unit_price[]" id="unit_price"&gt;&lt;/td&gt;'+
          '&lt;td&gt;&lt;input type="text" style="width: 45px" size="30" name="quantity[]" id="quantity"&gt;&lt;/td&gt;'+
          '&lt;td&gt;&lt;input type="hidden" name="tax_id" id="tax_id"&gt;&lt;label class="tax_name"&gt;N/A&lt;/label&gt;&lt;input type="hidden" name="tax_rate[]" id="tax_rate"&gt;&lt;/td&gt;'+
          '&lt;td&gt;$&lt;input type="text" value="0.00" size="10" readonly="readonly" name="net_price" id="net_price" class="read_only_text right_align_text" style="background-color: #fff;border:none;width: 100px;box-shadow:none "&gt;&lt;/td&gt;'+
          '&lt;td&gt;&lt;input type="hidden" value="false" name="net_price[]" id="net_price"&gt;&lt;a tabindex="-1" onclick="remove_invoice_item_fields(this); return false;" href="#" class="link_red link_small"&gt;remove&lt;/a&gt;&lt;/td&gt;'+
          '&lt;/tr&gt;';
      $('#items_tbody').append(tr);
  }
  </code></pre>