How to get value javascript from loop for ?

When load this code 

Why not alert `2` and `3`

<http://jsfiddle.net/3AaAx/41/>

```
<script>
$(document).ready(function(){    
    for (x = 1; x <= 5; ++x) {
      var test+x = x;
    }        
     alert(test2);
     alert(test3);

});
</script>

```