Question on resetting RecordSource on a 3 deep subform 1

[Paul7905]

I have a form named "Library Item Data" that contains a subform named "LocatorMain".

The LocatorMain subform contains a datasheet subform named "LocatorQuantity"

I need to allow the user to requery the subform "LocatorQuantity" so I put a control button on the subform "LocatorMain" and in the on-click event, placed the following code:

Forms![Library Item Data]![LocatorMain]![LocatorQuantity].RecordSource = "LocatorAll" (LocatorAll is the name of a query)

Access gives me the error message :

Object Does Not Support this Property or Method

Perhaps someone might have an idea how to code this ?
I have been able to successfully change the record source on forms before but this is the first time i have had to do it on a form that has a subform with a subform (3 deep)

Thanks

Paul