title: replace url of Ext.data.store
body: <p>I have <code>StoreBaseOn</code> declared, and I want to change the URL of it and then load it, as my code need to do so. How to change the URL?</p>
  
  <p>declared code:</p>
  
  <pre><code>StoreBaseOn =  new Ext.data.JsonStore({
      url: [myurl],
      root: 'rows',
      idProperty: [myID],
      autoLoad: true,
      remoteSort: true,
      baseParams: [myParam],
      fields: ['id', 'age']
  });
  </code></pre>
  
  <p>I know how to change param e.g. <code>StoreBaseOn.setBaseParam('group', the_group);</code>
  But how to just change the URL?</p>