All controls which allow absolute positioning have 3 standard properties:
x - this is the X coordinate.
y - this is the Y coordinate.
z - this is the Z coordinate.
The x- and y-value is measured from the top left corner of the page.
The z-value indicates the drawing sequence - the layer. The layer information becomes important if controls overlap - the control with the higher z-value is drawn on top of the control with the lower z-value.
