Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
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.
The window.mozInnerScreenX
property is a floating point, read-only value; it has no default value.
Not part of any W3C technical specification or recommendation.