You could also call the form with your main form as parameter, especially if you need to do a bit more with your main form. Create a new property, ie. oCallingform in your childform and call it like this:

do form childform with thisform

In the init-event of your childform do this:

lParameters oForm
thisform.oCallingform = oForm

Then you can reference your mainforms.properties and methods.

Best regards

Thomas