EditMask controls
The Spin property specifies whether the control is defined as a spin control that contains up and down arrows that the user can click to cycle through fixed values.
To make an EditMask into a spin control:
Select the Spin Control check box on the Mask tab page of the control’s Properties view.
The Spin property takes a boolean value.
The following line specifies that the user can cycle through values in an EditMask:
em_1.Spin = TRUE
