Img border = "0" class = "borderx" id = "pic_15132": benim Web inside "http://www.my_web_page" Ben böyle bir şey var

I wanna know which parameter did I have to use inside preg_match_all("") to retrieve only the number. Here is what I tried but my result is: _15132

$webpage = file_get_contents("http://www.my_web_page");

   preg_match_all("#_([^>]*)[0-9]{6}#", $webpage , $matches)
        foreach($matches[0] as $value) 
            { 
                echo $value . "<br>"; 
            }

Teşekkürler,