Q:

Is it possible to declare a Global  variable that gets used for all forms?

I am wondering if there is a way to declare a Global HTML- tag, that gets submittet with each form that gets called.
I mean something in the way like this:
<input type="hidden" name="x" value="200">
<form action="test.php" method="POST" enctype="multipart/form-data">
  #Some Form-Stuff
</form>
<form action="test.php" method="POST" enctype="multipart/form-data">
  #Some more Form-Stuff
</form>

And in both of these Forms, when a Submit is being made, there is supposed to be the Global hidden Input-Tag that gets delivered with the rest.
I already tried it and it didnt work, but I wonder if there is just something that is missing or if there is a similar or better way to accomplish this.
Would appreciate your help.
EDIT:
What I want in my current Project is to let the User <SELECT> an option that represents like an Folder in which there will be displayed data that is inside that folder. 
I dont want the User to have to Select the Folder again after each click and the folder has to be submitted every time to the php-script so that it can handle data accordingly to the folder selected.
My Question in this case however still remains on wether you can or cannot make a <input> tag global or not, if it´s permanent or not doesnt matter.

A:

Either include the following in your form
<input type='hidden'>

It is great for passing values without much code.
Or set it as a cookie/session variable as required.

