program define drtext
    version 4.0

    local xl      = `1'
    local yl      = `2'
    local centopt = `3'
    local txt     = "`4'"

    local xl = int($AX * `xl' + $BX)
    local yl = int($AY * `yl' + $BY)
    gph text `yl' `xl' 0 `centopt' `txt'

end