private void BindList()
{
string fromdate = ToSQL.SQLDateNonHour(txtFromDate.Text);
string todate = ToSQL.SQLDateNonHour(txtToDate.Text);
DataSet ds = _db.ExecuteQuery("select * from dbo.Contact where (" + fromdate + " is null or DateCreated >=" + fromdate + ") and (" + todate + " is null or DateCreated <= " + todate + ")");
gvContacts.DataSource = ds;
gvContacts.DataBind();
this.gvContacts.UseAccessibleHeader = true;
this.gvContacts.HeaderRow.TableSection = TableRowSection.TableHeader;
}