# DisplayScreen

Displays the bitmap(s) of the specified screen (or screens).

### Synopsis

`Err DisplayScreen (Item screenItem0,Item screenItem1)`

### Description

This call displays the bitmap(s) of the specified screen (or screens). The screenItem0 argument specifies the screen to be added to the display. For a stereoscopic or interlaced display, the screenItem1 argument can specify a second screen structure to be displayed in the odd field of the video frame.

The second argument can be NULL, or the same as the first, to specify a simple single-screen display.

### Arguments

screenItem0
  Item number of the screen that is to be added to the display.

screenItem1
  Optional item number of the screen that is to be added to the second (the odd) field of the display frame.

### Return Value

The call returns 0 if successful or an error code (a negative value) if an error occurs.

GRAFERR_NOTOWNER is returned if the screen item(s) specified are not owned by the current task and have not been opened with `OpenItem()` calls.

GRAFERR_SGNOTINUSE is returned if `AddScreenGroup()` has not been called for the screenGroup containing the specified screen(s).

GRAFERR_MIXEDSCREENS is returned if the specified screen items belong to different screenGroups.

### Implementation

Folio call implemented in the Graphics folio V20.

### Associated Files

graphics.h, graphics.lib

### See Also

``AddScreenGroup`(), ModifyVDL(), SetVDL(), SubmitVDL()`