__construct([string orientation [, string unit [, mixed size]]])
orientationP o Portrait (normal)
L o Landscape (apaisado)
P.
unitpt: punto
mm: milimetro
cm: centimetro
in: pulgada
mm.
sizeA3
A4
A5
Letter
Legal
unit).
A4.
$pdf = new FPDF('P','mm',array(100,150));