Write value in hide field

[yberges]

hello
i use post info to receive some value in php that i insert in form template
question how to write this value in fabrik hidden field ?
regards

 

[yberges]

to be more clear with code
in my article i have
<form style="display:none" id="idLogement" method="POST" action="<?php echo JUri::base(true) ?>/location/nos-offres-de-location/ce-logement-m-interesse">
<input type="hidden" value="<?php echo $this->item->id; ?>" name="id" />
</form>
and i send it by jquery
and i my form view i have
$id = isset($_POST['id']) ? $_POST['id'] : false ;
=> if ... to find more information

problem if form is reloaded (validation error) => post id was lost and form sin't good
thanks