在Imagebutton上添加标准属性

protected void Page_Load(object sender, EventArgs e)    {        //this.btnOk.Click += new EventHandler(btnOk_Click);        LblMessage.Visible = false;        ibtnOK.Attributes.Add("onmouseover", "this.src='../App_Themes/DefaultThemes/Images/Common/loginba.png'");        ibtnOK.Attributes.Add("onmouseout", "this.src='../App_Themes/DefaultThemes/Images/Common/loginb.png'");    }