PropertyHandle :: FillData - Fill instance from external one
The function copies all fields without references from the instance passed to the function into the selected instance.
Return value:  Success ( logical  )
Implementation details
logical 
PropertyHandle  :: FillData ( ::Instance instance )
- instance
 - Instance area
Instances do have the type of the referenced property handle (collection type). The instance contains a pointer to a properly structured instance area. You can use the !-operator or the GetData() function to check whether the instance refers to data or not. 

