title: Extjs 3, Borderlayout didn't show the North
body: <p>In the ExtJS 3, I create a panel like below, I set it to BorderLayout, but it will NOT show the north region, although it will show the center part. </p>
  
  <p>Please help. </p>
  
  <pre><code>MyContainer = Ext.extend(Ext.Panel, {
      initComponent: function () {
          var period_start = new Ext.form.TextField({
              id: 'PERIOD_START',
              fieldLabel: 'PERIOD START',
              allowBlank: true,          
              width: 250
          });
          var tmpPanel = new Ext.Panel();
          tmpPanel.add(period_start);
  
          var period_start1 = new Ext.form.DateField({
              id: 'PERIOD_START1',
              fieldLabel: 'PERIOD START',
              allowBlank: true,
              width: 250
          });
          var tmpPanel1 = new Ext.Panel();
          tmpPanel1.add(period_start1);       
  
          var config = {
              layout: 'border',
              items: [
                  {
                      region: 'north',
                      layout: 'fit',
                      minHeight: 150,
                      items: [tmpPanel]
                  },
                  {
                      region: 'center',
                      layout: 'fit',
                      items: [tmpPanel1]
                  }
              ]
          };
  
        .....
      }
  </code></pre>