title: Javascript number conversion
body: <p>why the conversion fail?</p>
  
  <pre><code>var ccc=10206229832728593;
  alert("saveme.php?id="+ccc.toString() ) ;
  
  var ccc=10152714408613803;
  alert("saveme.php?id="+ccc.toString() ) ;   
  </code></pre>
  
  <p>the first var is decreased by 1 and the second one is increased by 1.
  I'm going crazy! what i wrong?</p>