%N ctrlchck %F $MIR/src/subs/ctrl.for
%D Check if a particular buttons has been pushed.
%P jm
%: user-interaction, control-panel
%B
        subroutine CtrlChck(name,changes,val1,val2)

        implicit none
        character name*(*)
        integer changes,val1,val2

  This checks if a particular panel item has been modified and returns
  its current value.  If the item has not been previously accessed,
  `changes' will return with a zero value and `val1' and `val2' will
  be returned undefined.

  Input:
    name       The name of the item.
  Output:
    changes    The number of times the item has been changed.
    val1,val2  Two values associated with the item.
