Write a PHP program to compute the sum of the prime numbers less than 100

<?php
$primes = array();
$is_prime_no = false;
for ($i = 2; $i<100; $i++) {
     $is_prime_no = true; 
        for ($j = 2; $j<=($i/2); $j++) {
                if ($i%$j==0) {
                          $is_prime_no = false;
                                  break;
                                }
                   }
        if ($is_prime_no) {
               array_push($primes,$i);
                  }
        if (count($primes)==100) {
               break;
                  }
}
echo array_sum($primes)."\n";
?>