Marks a control as selected. This will normally be displayed in reverse video, but it depends upon the Windows color scheme that the end-user has chosen.
Possible values are true and false. If the value is true, the control will be marked as selected. If the value is false, the selection indication will be removed from the control.
This function is not supported in the RoleTailored client.
This function can only be used in thetrigger.