There is a _CHECKBOX control (TYPE == 14).
 
Syntax:
Window.AddControl(id,14,X,Y,WIDTH,HEIGHT,"Text label");
Sample:
Window.AddControl(888,14,0,32,80,12,"Checked option");
Description:
This CHECKBOX is checked. A check box consists of a square box and application-defined text (label) that indicates a choice the user can make by selecting the button. Applications typically display check boxes in a group box to permit the user to choose from a set of related, but independent options.

X, Y, WIDTH, HEIGHT : - The dialog units. The horizontal base unit is equal to the average width, in pixels, of the characters in the system font; the vertical base unit is equal to the height, in pixels, of the font. Furthermore, each horizontal base unit is equal to 4 horizontal dialog units; each vertical base unit is equal to 8 vertical dialog units.

 
  GUI for script  
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