[paragui-users] How to pass a crtain userdata to PARAGUI_CALLBACK ?

[juri]

  Hi,

i dom´t fully understand how to access userdata in PARAGUI_CALLBACK.
Let´s say i have a Listbox (or a Radiobutton). And i want to use the 
name or the ID or The actual Content in the CALLBACK function. Like: I 
klick the ListBoxItem "AnItem". "AnItem" contains the Text 
"ThisIsASample". Now i klick The button, and i want to have a pointer to 
 "ThisIsASample" to proceed. Hope you understand what i mean...

Also if anybody could point my in the right direction how i can find out 
these things myself that would be nice.

THX, John