ช่วยดูโค๊ดให้หน่อยค่ะ Error Incorrect syntax near '.'

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Configuration;
using System.Data.SqlClient;
using System.Data;
using System.Net.Mail;
using System.Web.Security;
using System.Text.RegularExpressions;
using System.Drawing;

public partial class contractExpire : BasePage
{

    protected void Page_Load(object sender, EventArgs e)
    {

        if (!Page.IsPostBack)
        {
            Binddata();
        }
    }

    private DataTable Getcontact()
    {


        using (SqlConnection cn = new SqlConnection(Globals.Con))
        {

          string sql = " SELECT tbx_TranContact.TranID,tbx_TranContact.PropViewer,tbx_TranContact.DateIssue,tbx_TranContact.DateAppr,tbx_TranContact.ContactTitle ";
            sql = sql + " tbx_Validity.ValidTime";
            sql = sql + "  FROM tbx_TranContact INNER JOIN ";
            sql = sql + " tbx_Validity ON tbx_TranContact.ValidID = tbx_Validity.ValidID  ";
            sql = sql + "WHERE (tbx_TranContact.TranType ='E')AND (tbx_Validity.ExpireDate) < " + DateTime.Now.ToString() + ")";


            SqlCommand cmd = new SqlCommand(sql, cn);
            cmd.CommandType = CommandType.Text;


            cn.Open();

            DataTable dt = new DataTable();


            System.Data.Common.DbDataReader dr;
            dr = cmd.ExecuteReader();

            dt.Load(dr);


            return dt;
        }
    }

    private void Binddata()
    {
        DataTable dt = new DataTable();
        dt = Getcontact();

        grdSearch.DataSource = dt;
        grdSearch.DataBind();
    }

    protected void grdSearch_RowCreated(object sender, GridViewRowEventArgs e)
    {

    }
    protected void grdSearch_RowDeleting(object sender, GridViewDeleteEventArgs e)
    {

    }
    protected void grdSearch_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            e.Row.Attributes.Add("OnMouseOver", "style.backgroundColor='#F9E9F2'");
            e.Row.Attributes.Add("OnMouseOut", "style.backgroundColor='#FFFFFF'");

            
        }

    }
    protected void grdSearch_RowCommand(object sender, GridViewCommandEventArgs e)
    {

    }
    protected void grdSearch_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        grdSearch.PageIndex = e.NewPageIndex;
        Binddata();
    }

}