Summary
Gets the X coordinate of the top-left corner of the window's viewport, in screen coordinates.
Note: This coordinate is reported in CSS pixels, not in hardware pixels. That means it can be affected by the zoom level; to compute the actual number of physical screen pixels, you should use the 
nsIDOMWindowUtils.screenPixelsPerCSSPixel property.Syntax
screenX = window.mozInnerScreenX;
Value
- screenX stores the window.mozInnerScreenXproperty value.
- The window.mozInnerScreenXproperty is a floating point, read-only value; it has no default value.
Specification
Not part of any W3C technical specification or recommendation.