Fullsceen bgrnd image TopLeft aligned?

i have fullscreen proportional scaling bgrnd images...
but they re always centered.
i need the TopLeft or TopRight aligned. - but still fullscreen proportional scaling.

is there a way to do so?

i have this code so far, but its centered, so parts at the top get cutt off sometimes:

Code:

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onClipEvent(load){
        // Assigning Vars for the middle of screen
        var middleX = Stage.width/2;
        var middleY = Stage.height/2;
       
        // Position the object in Middle
        this._x = middleX;
        this._y = middleY;
       
        // Scaling the background to fit
        // with the width & height of stage
        this._width = Stage.width;
        this._height = Stage.height;
       
        // Check if the image grew bigger horizontally or vertically
        // and adjust the other one to match with maintain aspectratio
        this._xscale > this._yscale ? this._yscale = this._xscale : this._xscale = this._yscale;

       
        // Assign this function to the object with same
        // actions everytime the Stage is resized
        // =============================================
        Stage.addListener(this)
        this.onResize=function(){
                // Assigning Vars for the middle of screen
                var middleX = Stage.width/2;
                var middleY = Stage.height/2;
       
                // Position the object in Middle
                this._x = middleX;
                this._y = middleY;
               
                // Scaling the background to fit
                // with the width & height of stage
                this._width = Stage.width;
                this._height = Stage.height;
       
                // Check if the image grew bigger horizontally or vertically
                // and adjust the other one to match with maintain aspectratio
                this._xscale > this._yscale ? this._yscale = this._xscale : this._xscale = this._yscale;

        }
}

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