Something

<?if ($_POST['count'] != ""){ if (is_numeric($_POST['count'])){  $time_start = microtime(1);  $x = $_POST['count'];  for($i=1;$i<=$x;$i++) {    $f=sqrt($i);   for($z=1;$z<=$f;$z++) {     $y=$i%$z;    if($y==0){     $l++;    }    if($l>=2){     break;    }   }   if ($l<=1){     echo "$i, ";    $b++;    }   $l=0;  }  $time_end = microtime(1);  $time = $time_end - $time_start;  echo "<br><b>[ Found first $x prime numbers in $time seconds ]</b>"; } else {  echo "<br><b>Please enter a number!</b>"; }}?>