I have two select tags which will get information from database. One takes from product_category table and other takes from product. I want to make the products select tag depend on the product_category select tag. For Example I have two categories of Medicines, one is capsules and other is tablets. I want the product select tag to display me the names of the capsules when I select capsules in the product_category select tag. How do I make it dependent? Here is the code for those select tags:

        Select Category
        
            $ctg_name";
            }
            ?>    
        
    
   

        Select Product
        
            $product_name";
            }
            ?>