如何在select onChange事件上重定向到其他方式？

I'm trying to make a product browser selection interface that when I click the selection of productType in the column1, the column2 will appear the product with the selected productType by fetching information in the database (SELECT productName from products WHERE productTYPE = 1).

I've done it with ajax, but it turns out ajax is not permitted in this assignment(really sad!)

I can't come up with the solution without ajax. So Is there any way to make a post/get request with parameter and redirect to the self page(with self-post technique), only after I select a productType in the column1(onChange event on select element)

What if you just outputted all the Products in a single select when you load the page and hide all the options by default then you can unhide the correct ones when you select a Product Line from column1.

A second option is to put multiple selects on the page when load, one for each Product Line and then hide all those selects by default and show/hide them as the appropriate column1 is selected.