gre.to_alignment(
    alignment
)
		    Generate a numeric alignment value based on a symbolic, case sensitive, alignment string
Parameters:
        alignment  A string value of "left", "right", "center", "top", "bottom"
Returns:
        A numeric value for alignment corresponding to gre.LEFT, gre.RIGHT, gre.CENTER, gre.TOP, gre.BOTTOM
Example:
-- Set an alignment variable to be left aligned
local alignment = gre.to_alignment("left")
gre.set_value("myLayer.myControl.horizontalAlignment", alignment)