Avoid to resent POST or GET on page reloads.
Retun true if reload detected.

To use it, generate a random hash in the form, for example:

 
email: 
name: 
comment: 

On the process page, add antiReload to check if F5 was pressed:

if (!$wv->antiReload($antireload)) {
    //Code for processing the form.
}