function CreateStudents(){
        var res;
        Ext.MessageBox.show({
            title: '创建学生学习帐号',
            msg: '输入学生姓名：',
            width:300,
            modal: true,
            closable: false,
            defaultTextHeight: 150,
            multiline: true,
            animEl: 'dialog',
            buttons: Ext.MessageBox.OKCANCEL,
            fn: function(btn,text){
                if(btn=='ok'){
                    if (text.trim()!=""){
                        Ext.fly('hStudents').value=text;
                        res= true;
                    }
                    res= false;
                } // end of "btn=='ok'
            }
        });
        alert(res);
        return res;
    }