protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            queryControl();
        }
    }
    public void queryControl()
    {
        //System.Web.UI.WebControls.TextBox control;
        foreach (System.Web.UI.Control control in this.Controls)
        {
            if (control is System.Web.UI.WebControls.TextBox)
            {
                System.Web.UI.WebControls.TextBox tb = (System.Web.UI.WebControls.TextBox)control;
                tb.BackColor = System.Drawing.Color.Red;
                tb.Visible = false;
            }
        }

    
    }