| **Navigation:**  [[introduction.htm|Language Reference]] > [[chapter runtime properties.htm|App C - PROP: Runtime Properties]] > Complete Property List >====== PROP:Threading ====== | [[prop thread.htm|{{btn_prev_n.gif|Previous page}}]][[chapter runtime properties.htm|{{btn_home_n.gif|Return to chapter overview}}]][[prop ticks.htm|{{btn_next_n.gif|Next page}}]] | | || Property of the SYSTEM built-in variable which, when set to zero (0), disables all MDI behavior and turns the application into an SDI application. **Example:** ** PROGRAM** **!Data declarations** ** CODE** ** IF SomeCondition = TRUE** **  SYSTEM{****PROP:Threading****} = 0   !Set to SDI behavior** ** END**