Dear All,

How could I go back by (Back botton) on Browser, Without losing POST data ?

I have search page, after I posting keyword, then I get the result page, when I click to any of results, then I would go back to result page, I see:
"Webpage has expired"

Then I have to go to the search page again, and write my keywords again...

So, How to save my keywords to go back easily to the result page ?

Best Regards,
A. Mansouri

You cannot.
The Post form method have been designed to not be persistent.

But often, if you hit the reload button, your browser will ask you if you want to re-send the same form again

There is a way to keep the search results, I've seen it on other sites but I'm not sure how you do it.

There are tools, and plugins that can save the post datas, and re-populate the fields when you come back to the page (look for roboform, or robotform...), but there are no automated way to avoid the "datas expired" screen.