title: MySQL Query group by to get the last id
body: <p>this is my table  </p>
  
  <pre><code>id | sender | receiver | msg  
  -----------------------------
  1  | jon    | jack     | buzz ...  
  2  | jack   | jon      | ?  
  3  | adel   | jon      | met me soon  
  4  | jon    | adel     | okay  
  5  | alex   | jon      | where ar u ?  
  6  | jon    | adel     | okay  
  7  | adel   | alex     | don't forget the party  
  8  | jon    | jack     | may i borrow ur car 
  9  | alex   | adel     | of course
  10 | jack   | jon      | ok
  11 | jack   | jon      | watch the gas
  12 | alex   | jon      | i'm dying here
  13 | jon    | alex     | 5 mnt ..
  </code></pre>
  
  <p>and i want get list last messages of jon with his friend like this</p>
  
  <pre><code>id | sender | receiver | msg
  -------------------------------------------
  13 | jon    | alex     | 5 mnt ..
  11 | jack   | jon      | watch the gas
  6  | jon    | adel     | okay
  </code></pre>
  
  <p>How to query, to get that result ?</p>