I'am triyng to create a form where i have 2 comboBox and 2 textbox, when the selection changes on the first combo , the content of second also changes. i have to use onchange=form.submit()

the problem is, i want to have a button to finish the selection and save all the data to a database, but if i have diferent forms, i will not get the last change on the text boxs, only th last change when i changed the combobox.

Using the same form how can i know if it was the button pressed or the combochange that executed the submit ??

here's an example

Could you help me