Burst

$burst=$_GET["burst"];
$bid=0;
$str=$burst;
while(1)
{
$first_at=stripos($str,'@');
if (!$first_at)
{
exit;
}
$first_space=stripos($str,' ',$first_at);
$first_period=stripos($str,'.',$first_at);
$ff=$first_space;
if ($first_period<$ff)
{
$ff=$first_period;
}
$user=substr($str,$first_at+1,$ff-$first_at-1);
$sql="SELECT * FROM users WHERE user=$user";
$result=mysql_query($sql);
if (mysql_num_rows($result)!=0)
{
while($row=mysql_fetch_array($result))
{
$id=$row["id"];
$sql="INSERT INTO burst_user_ref(burst,id) VALUES($bid,$id)";
$result=mysql_query($sql);
}
}
$str=substr_replace($str,'@'.$user,0)
}