First defined in: FKiSS4
The letchild action sets the value of variable to the
lowest-numbered attached child object for target.
If no child object is attached to target, 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:
;@ letchild(C, #5)
;@ letchild(C, VarParent)