How to open a child window from another child window

Hi, i got this odd situation in which after opening a child window i want to open another child window from the first child window. the problem is that the constructor of the second child window requires the reference of parent window, but since i m opening it from the first child window therefore i cannot pass 'this' as an argument of constructor. Please tell me how can i achieve this. or if there is another way to open a new form from a child window please do tell me that also. Thanx bye.