Line breaks and colors

<?php
require('fpdf.php');

class PDF extends FPDF
{
function Header()
{
    global $title;

    //Arial bold 15
    $this->SetFont('Arial','B',15);
    //Calculate width of title and position
    $w=$this->GetStringWidth($title)+6;
    $this->SetX((210-$w)/2);
    //Colors of frame, background and text
    $this->SetDrawColor(0,80,180);
    $this->SetFillColor(230,230,0);
    $this->SetTextColor(220,50,50);
    //Thickness of frame (1 mm)
    $this->SetLineWidth(1);
    //Title
    $this->Cell($w,9,$title,1,1,'C',true);
    //Line break
    $this->Ln(10);
}

function Footer()
{
    //Position at 1.5 cm from bottom
    $this->SetY(-15);
    //Arial italic 8
    $this->SetFont('Arial','I',8);
    //Text color in gray
    $this->SetTextColor(128);
    //Page number
    $this->Cell(0,10,'Page '.$this->PageNo(),0,0,'C');
}

function ChapterTitle($num,$label)
{
    //Arial 12
    $this->SetFont('Arial','',12);
    //Background color
    $this->SetFillColor(200,220,255);
    //Title
    $this->Cell(0,6,"Chapter $num : $label",0,1,'L',true);
    //Line break
    $this->Ln(4);
}

function ChapterBody($file)
{
    //Read text file
    $f=fopen($file,'r');
    $txt=fread($f,filesize($file));
    fclose($f);
    //Times 12
    $this->SetFont('Times','',12);
    //Output justified text
    $this->MultiCell(0,5,$txt);
    //Line break
    $this->Ln();
    //Mention in italics
    $this->SetFont('','I');
    $this->Cell(0,5,'(end of excerpt)');
}

function PrintChapter($num,$title,$file)
{
    $this->AddPage();
    $this->ChapterTitle($num,$title);
    $this->ChapterBody($file);
}
}

$pdf=new PDF();
$title='20000 Leagues Under the Seas';
$pdf->SetTitle($title);
$pdf->SetAuthor('Jules Verne');
$pdf->PrintChapter(1,'A RUNAWAY REEF','20k_c1.txt');
$pdf->PrintChapter(2,'THE PROS AND CONS','20k_c2.txt');
$pdf->Output();
?>