I am new to AJAX. I have a MySQL database with list of categories and subcategories. I have created a table where the first column contains the list pf categories and the second column calls the subcategories from an external php page called subcats where i echo the subcats.

I used xmlhttp.open for the <div id="getsubcats"> this is the second column.

I have a form below the table. I want to change the form fields ased on subcat selection. How do i do that?