PHP - links automaticos

<?php

$valor1 = file_get_contents('fichero1.txt');

$valor2 = file_get_contents('fichero2.txt');

$valor3= $valor2 - $valor1;

echo $valor3;

if( $valor3  == 25)

{

	echo "<script language='JavaScript'>";

	echo "location = 'white2.php?modo=1&ok=1'";

	echo "</script>";

}

if( $valor3  == 100)

{

	//enviar una respuesta para que la pantalla no este apareciendo

	echo "<script language='JavaScript'>";

	echo "location = 'yellow2.php?modo=1&ok=1'";

	echo "</script>";

}

if($valor3 == 200 )

{

	echo "<script language='JavaScript'>";

	echo "location = 'red2.php?modo=1&ok=1'";

	echo "</script>";

}

?>

<?php

$opc = 1;

switch($opc){

    case 1:

        header('location: page1.php?var=1');

        exit;

        break;

    case 2:

        header('location: page2.php?var=2');

        exit;

        break;

    case 3:

        header('location: page3.php?var=3');

        exit;

        break;

}