function MouseEvent(e)
{
    /* format is
    if ( understand Firefox DOM property/object )
    {
    use FF DOM property/object
    }
    else
    {
    use IE DOM property/object
    }
    */

    // code adapted from Ajax for Dummies by Steve Holzner, PhD
    // Copyright 2006 Wiley Publishing.
    if (e)
    {
        this.evt = e;
    }
    else
    {
        this.evt = window.event;
    }

    if (this.evt.pageX)
    {
        this.left = this.evt.pageX;
    }
    else
    {
        this.left = this.evt.clientX;
    }

    if (this.evt.pageY)
    {
        this.top = this.evt.pageY;
    }
    else
    {
        this.top = this.evt.clientY;
    }

    if (this.evt.target)
    {
        this.target = this.evt.target;
    }
    else
    {
        this.target = this.evt.srcElement;
    }
    // end adapted code

    if (this.evt.layerX)
    {
        this.offsetX = this.evt.layerX;
    }
    else
    {
        this.offsetX = this.evt.offsetX;
    }

    if (this.evt.layerY)
    {
        this.offsetY = this.evt.layerY;
    }
    else
    {
        this.offsetY = this.evt.offsetY;
    }

    

}