<select class="products-dropdown" name="lease-product" id="sel-lease-product" onchange="hideDiv(this)">
                        <option value="0"><?php _e('Select product', 'wp-woo-leasing'); ?></option>

                      <script type="text/javascript">
                  	function hideDiv(elem) {
                      if(elem.value == 0)
                        document.getElementById('product-description').style.display  = "none";
											  }
                      </script>