Procedure FreeVirtualVariablesPrefixed([group: Integer=0])
(For how to use groups, see the advanced topic VirtualVariable Groups)
This function removes all VirtualVariables in the specified group from memory.
Specify a group value of -1 to clear VirtualVariables from all groups.
If you prefer, to distinguish this procedure from the similar function FreeVirtualVarable, you can use ClearVirtualVariables([groupd: Integer=0]) instead.