title: Scope usage in ExtJS events and functions
body: <p>I am using ExtJS 4 for my Web application development. I need to fire <a href="http://www.sencha.com/products/extjs" rel="nofollow">extjs</a> <a href="http://en.wikipedia.org/wiki/Event" rel="nofollow">event</a> many time. Till now I did all stuffs without adding scope while firing event. It's working fine, but want to know what is purpose of third parameter which is scope and also it's optional. I am giving two snap-shots here. can Anyone help me to understand scope, the third parameter of <a href="http://docs.sencha.com/extjs/4.2.1/#!/api/Ext.util.Observable-method-on" rel="nofollow">on</a> method? Thanks in advance. Sorry for my English.</p>
  
  <pre><code> store.on('load',function(store, records, successful, eOpts){
  
           /**do some stuff here..*/
    });
  
  
  
  store.on('load',function(store, records, successful, eOpts){
  
           /**do some stuff here..*/
    },[scope]); //scope added
  </code></pre>