当前上下文中不存在名称“Common”

protected void Button1_Click(object sender, EventArgs e)
    {
        string search = "";
        if (!string.IsNullOrEmpty(TextBox2.Text))
        {
            search += "and Uname like'%" + Common.ForamatParameter(TextBox2.Text) + "%'";
        }
        string Sql="select*from kaoqin";
        PageNavigator1.Total = 1;
        PageNavigator1.Query = Sql;
        
    }