Query Date from SQL Server

[mixarstudio]

now i used Ajax Calendar Extender to select the date
and show back to textbox name, txtDate.
i show in this format Fri 06 Feb 2009

and then i must use this date to query
data from my database.

i have some problem about date field
in my DB, it keep in this format, 2009-02-06
it has SqlDbType.Date to collect in this field.

how can i use txtDate field in query date from my DB

i use like this:

StringBuilder sb = new StringBuilder();
sb.Append("select Order_ID as OrderID, ");
sb.Append("Order_Date as OrderDate, ");
sb.Append("Order_Time as OrderTime, ");
sb.Append("Order_Status as OrderStatus ");
sb.Append("from tranOrder ");
sb.Append("where (Order_ID = @OrderID) ");
sb.Append("and (Order_Date = @OrderDate) ");

string sqlViewOrder = sb.ToString();
DataTable dtOrderStatus;
SqlCommand com = new SqlCommand();
com.CommandType = CommandType.Text;
com.CommandText = sqlViewOrder;
com.Parameters.Clear();
com.Parameters.Add("@OrderID", SqlDbType.VarChar).Value = Session["orderID"].ToString();

DateTime ordDate = DateTime.Parse(txtDate.Text);
com.Parameters.Add("@OrderDate", SqlDbType.Date).Value = ordDate;

com.Connection = Conn;
SqlDataReader dr;
dr = com.ExecuteReader();

but when i run they told me "String was not recognized as a valid DateTime."

how can i solve this problem?

thanks a lot for every answers