File Content: categoryAjax.php <?php include("../library.php"); $q=$_GET['q']; $_SESSION['category']=$q; ?> <label><b>Product Category</b></label> <select class="form-control" name="productCatId" requited onChange="productAjax(this.value)"> <option>select product category</option> <?php $result=$mysql->m_Query("select distinct(productId) from tblproduct where categoryId=$q"); while($row=$mysql->m_FetchObject()) { $result=$mysql2->m_Query("select * from tblproductcategory where id=$row->productId"); $row2=$mysql2->m_FetchObject(); echo "<option value=$row2->id>$row2->name</option>"; } ?> </select> Submit