EXT 可以这么使用
首先申明一下，本人不是专门搞ExtJS的

每个页面都可以使用俩个自定义的JS作为使用ExtJS补充

ui-style.js,主要是覆盖ExtJS默认的属性，如日期格式默认是mm/yy/dd,可以改成yy-mm-dd,如下内容供参考

Ext.form.Field.prototype.msgTarget = 'under';Ext.form.FormPanel.prototype.labelWidth= 80;  Ext.form.FormPanel.prototype.labelAlign='left';Ext.form.BasicForm.prototype.waitTitle = '处理中';Ext.grid.DateColumn.prototype.format   = "Y-m-d";Ext.form.DateField.prototype.format = "Y-m-d";//pagePAGE_LIMIT  = 10Ext.PagingToolbar.prototype.displayInfo=true;Ext.PagingToolbar.prototype.displayMsg='从{0} 到 {1} 总共 {2} ';Ext.PagingToolbar.prototype.emptyMsg = "无记录";Ext.PagingToolbar.prototype.pageSize=PAGE_LIMIT;//gridExt.grid.GridPanel.prototype.stripeRows=true;Ext.BLANK_IMAGE_URL = window.contextPath +'/resource/extjs/skins/default/images/default/s.gif';//comboxExt.form.ComboBox.prototype.mode = "local";Ext.form.ComboBox.prototype.triggerAction = "all";Ext.form.ComboBox.prototype.valueField = "id";Ext.form.ComboBox.prototype.displayField = "displayText";//Ext.form.TextField.prototype.width = 140;Ext.form.ComboBox.prototype.width = 140;//其他变量MUST_SELECT_ONE = "请选中一行";SERVER_ERROR = "服务器错误，请稍后再试"OPERATION_SUCCESS="操作成功"

另外一个是修改ExtJS默认处理，如ajax load出错，则给出统一提示，再比如当ajax请求，锁定页面上的某个button或者窗口等，例子如下：

Ext.data.Store.prototype.listeners = {            exception:function(dataProxy, type, action, options, response, arg) {            alert(SERVER_ERROR);                        }}Ext.Ajax.on('beforerequest', beforerequest, this);Ext.Ajax.on('requestcomplete', requestcomplete, this);Ext.Ajax.on('requestexception', requestexception, this);function beforerequest(conn,  options){var cmp = Ext.getCmp(options.maskId);if(cmp!=null){var xtype = cmp.getXType()if(xtype=="grid"||xtype=="form"||xtype=="panel"){cmp.el.mask('请稍等....', 'x-mask-loading');  }else{cmp.disable();}}}function requestcomplete( conn,  response,  options){var cmp = Ext.getCmp(options.maskId);if(cmp!=null){var xtype = cmp.getXType()if(xtype=="grid"||xtype=="form"||xtype=="panel"){cmp.el.unmask('请稍等....', 'x-mask-loading');  }else{cmp.enable();}}}function requestexception( conn,  response,  options){requestcomplete(conn,response,options);}

再次申明，我不是搞ExtJS的，不要问我ExtJS的问题啊，我不懂