title: EXTJS combobox change even code executed on page load
body: <p>I have created class for combobox, which object can be created whenever combobox need in project.</p>
  
  <p>now for every change event of every combo there can be different things to do, so I have not written any code in my combo class for combo change event.</p>
  
  <p>I need something like I can assign code to combo change event when i create it or after creating.</p>
  
  <p>So i write below code .</p>
  
  <pre><code>Ext.getCmp('combo1').on('change', Ext.getCmp('grid').getfilteredStore());
  </code></pre>
  
  <p>But issue with this code is : <code>Ext.getCmp('grid').getfilteredStore()</code> get triggered on page load only, not on <code>change</code> of combo.</p>
  
  <p>Below is code which create combo whenever required</p>
  
  <pre><code>Ext.create('Comboclass', { 
          id: 'comboId'});
  </code></pre>
  
  <p>Below is combo class</p>
  
  <pre><code>Ext.define('Comboclass', {
      extend: 'Ext.Container',
  
      initComponent: function () {
  
          Ext.apply(this, {
              items: [{
                  xtype: 'combo',
                  id: this.id,
                  store: store1
                  listeners: {
                      beforeselect : function (combo, r, index) {
                          if (r.data.id &amp;&amp; r.data.id &lt; 0) {
                              r.data.selectable = false;
                              return r.data.selectable;
                          }
                      },
                      change: function (field, newValue, oldValue) {
                          console.log('in dropdown');
                      }
                  }
              }]
          });
          this.callParent(arguments);
      }
  });
  </code></pre>
  
  <p>Can any one help to solve this issue?</p>
  
  <p>Thanks in advance.</p>