how to check the current value and the previous value

[tllcll]

Hi,

I would like to know how to check the current value and the previous value entered by user before changes.

for example, the form will allow user to enter customer number. The first time user enter 10 then change to 22

customer number : 10 -> change to 22

how do I get the previous value which is 10 in this case

[pclement]

In your scenario, when does the current value become the previous value? Is it when a user clicks on a button to submit a page?

What tool are you using to develop your web application?

[tienchihwang]

Hi,
You can use Javascript to save the previous value into a form hidden value. input type="hidden" name="saved_value" value="..."
Compare the saved_value with the current one when re-loading the page.

Sincerely,

Tien-Chih Wang