Where are you people ? I need help really ..

Here you are what I have done by now ( Just designing, I don not know how to write commands to open or close or to call ...etc ):

Now, I want the IDD_SLL_DIALOG opens when I press SLL button & create a new SLL object ( I have the code for it but I don not know where should I put it ).

And, when I press EXIT button ( on IDD_SLL_DIALOG ) I want the program return to IDD_TET_DIALOG not ending the whole program.