php collects beautiful pictures from a website

<?php
header("Content-type:text/html;charset=utf-8");
function GrabImage($url,$filename="") {
if($url==""):return false;endif;
if($filename=="") {
$ext=strrchr($url,".");
if($ext!=".gif" && $ext!=".jpg"):return false;endif;
$filename=date("dMYHis").$ext;
}
ob_start();
readfile($url);
$img = ob_get_contents();
ob_end_clean();
$size = strlen($img);
$fp2=@fopen($filename, "w+");
fwrite($fp2,$img);
fclose($fp2);
return $filename;
}
 
 
for($i=1;$i<8;$i++){
$url="http://www.topit.me/popular/20120420?p=".$i;
echo $url;
$file=file_get_contents($url);
 
$preg=&#39;/(.*)<div class="e">(.*)<\/div>(.*)/isU&#39;;
preg_match_all($preg,$file,$string);
set_time_limit(0);
 
foreach($string[2] as $key=>$value){
    //echo $value;
    $pattern_src = &#39;/href="(.*)"><img class="img" title="(.*)"/isU&#39;;
    preg_match_all($pattern_src,$value,$str);
    print_r($str."<br/>");
 
    $img=GrabImage($str[1][0],"","");
 
    if($img){
        echo &#39;sucess&#39;;
    }else{
        echo "false";
    }
}
 
}
?>