The PSM_PRESSBUTTON message simulates the choice of a property sheet button. You can send this message explicitly or by using the PropSheet_PressButton macro.
PSM_PRESSBUTTON wParam = (WPARAM) (int) iButton; lParam = 0;
| Value | Meaning | 
| PSBTN_APPLYNOW | Chooses the Apply Now button. | 
| PSBTN_BACK | Chooses the Back button. | 
| PSBTN_CANCEL | Chooses the Cancel button. | 
| PSBTN_FINISH | Chooses the Finish button. | 
| PSBTN_HELP | Chooses the Help button. | 
| PSBTN_NEXT | Chooses the Next button. | 
| PSBTN_OK | Chooses the OK button. | 
No return value.