1. Ext.Ajax.request
Ext.Ajax.request({  
                           url: '../xxx',method:"POST",params: {paramName: paramValue},success: function(resp,opts){  
                               //返回的对象Ext.util.JSON.decode(request.responseText)  
                               var respText = Ext.util.JSON.decode(resp.responseText);  
                               var msg= respText.msg;  
        Ext.MessageBox.alert('提示',msg);  
                           },failure: function(resp,opts){  
        //返回的对象Ext.util.JSON.decode(request.responseText)  
                               var respText = Ext.util.JSON.decode(resp.responseText);  
                               var msg= respText.msg;  
        Ext.MessageBox.alert('提示',msg);  
               }                             
                       });  

2. form.getForm().submit()
this.formPanel.getForm().submit({  
                                    waitTitle: "请稍候",waitMsg : '提交数据，请稍候...',success: function() {                                         
                                        myDialog.hide();  
                                        store.reload();  
                                    },failure: function(form,action) {                                          
                                        Ext.MessageBox.alert('提示',action.result.msg);  
                                        return;  
                                    },scope: this                                   
                                });