First defined in: FKiSS4
The letparent action sets the value of variable to the
current attached parent object for target.
If target is not attached to a parent object, variable
is set to -1.
variable
variable must be a variable name.
target
target may be an object number or a variable
representing an object number.
Example:
;@ letparent(C, #5)
;@ letparent(C, VarOrphan)