GET the next INPUT element in a table TR

Hello,

My app has an order. This order has products, which is chosen in a
select list.

each product is added by a partial like this:

   1. <tr>
   2. <td>
   3. <select><option>product1</option></select>
   4. </td>
   5. <td>
   6. <input name="product_price" />
   7. </td>
   8. </tr>

"Onchange" a product, the price is updated via ajax using rjs. thats
OK.
but, when I add another product, it update the first product price, of
course, because it have the same name and ID. But I can not change
this, so is there some way to get the next input element via
javascript? Selecting the next input element or something like this.

thnks a lot!!!

Have a look at jQuery, it's great for stuff like this.

I did search for this at jquery but i can´t find this stuff... could
you show me how?