title: Generate random number with a certain prefix what am i doing wrong
body: <p>I've been playing about with the uniqid but it started giving me the 13 long string.</p>
  
  <p>I'm looking for a prefix of 100 with up to 6 random numbers afterwards</p>
  
  <p>thanks any help appreciated</p>
  
  <pre><code>function generate_order(){
  
      $order_ref="";
      $a=uniqid(prefix,100);  
      $num4=array('0','1','2','3','4','5','6','7','8','9');
      $num=rand(0,9);
      $num2=rand(0,9);
      $num3=rand(0,9);
      shuffle($num4);
      //now the final
      $order_ref = $num4[0].$num4[3].$num.$num4[1].$num2.$num4[2].$num3.$num4[4];
  }
  </code></pre>