function __autoload($_className) {
require $_className.'.class.php';
}
//新建類？？
if (isset($_GET['index'])) {
$m=new Main($_GET['index']);
}else{
$m=new Main();
}
include $m->ui();

class Main{
private $index;
//構(gòu)造方法，初始化數(shù)據(jù)
public function __construct($index=''){
$this->index=$index;
}
//ui函數(shù)include相應(yīng)的包含文件
public function ui(){
if(empty($this->index)||!file_exists($this->index.'.inc')){ 
$this->index='start';
}
return $this->index.'.inc';
} 
}

if (isset($_GET['index'])) {
 $m=new Main($_GET['index']); //如果 $_GET['index'] 存在則將 $_GET['index'] 作為參數(shù)
}else{
 $m=new Main(); //否則使用默認(rèn)參數(shù)
}

<?php
class Main{
 private $index;
 //構(gòu)造方法，初始化數(shù)據(jù)
 public function __construct($index='')
 {
 $this->index=$index?$index:'';
 }
 //ui函數(shù)include相應(yīng)的包含文件
 public function ui()
 {
 if(empty($this->index)

!file_exists($this->index.'.inc'))
 { 
 $this->index='start';
 }
 return $this->index.'.inc';
 } 
}

<?php
function writefile($fname,$str){
 $fp=fopen($fname,"w");
 fputs($fp,$str);
 fclose($fp);
}
?>

<?php
$filename='test.txt';
$str='abc';
writefile($filename,$str);
?>