>Hi,
> I am using SDI form as main windows and child form inside it. Are there any function to retrieve the refence?

Do something like:

1) Launch the TL with NAME clause:

DO FORM TLname NAME Topform

2) Create a TL property, for example Child1
3) Launch child from TL like:

DO FORM childname NAME Thisform.Child1
or
Thisform.Child1 = CREATEOBJ('childclassname')

Child form is now an object of TL, and they can reference each other.