winapi - How to use DialogBox in Windows API -

i'm learning windows api weeks, got problem, code this

lresult callback mainwndproc(hwnd hwnd, uint message, wparam wparam, lparam lparam){ switch(message){   case(...)     dialogbox(hinstance,makeintresource(idd_mydialog),hwnd,(dlgproc)mydialogproc);     return 0; }  bool mydialogproc(hwnd hwnd, uint message, wparam wparam, lparam lparam){     switch (message){       ...            }     return false; } 

i don't know else should before use dialogbox should place enddialog(). idd_mydialog resource file created myself. don't understand hinstance , how it, think need simple example, can know how use dialogbox. thank helping!