title: Value does not change when in parameters
body: <p>I am having difficulties changing values sent in with parameters to a function, and I have no idea why it doesn't change the value outside of the function. What have I done wrong? =)</p>
  
  <pre><code>hero= {health:25}
  
  increasehealth(hero.health);
  
  function increasehealth(hp)
  {
  hp+=5;
  
  }
  
  alert(hero.health);
  </code></pre>
  
  <p><a href="http://jsfiddle.net/kkQC4/3/" rel="nofollow">Here is the script on jfiddle</a></p>
  
  <p>Thanks in advance!</p>