passing arguments in oracle command using vb.net
===

am writing code in vb.net .am using select statement in oracle command . when i pass arguments values through variable am getting error.

    my code
    ------
    chk1 = TextBox1.Text
    d1 = Date.Parse(chk1)


    --------
    --------
    try
       cn.Open()

            cmd = New OracleCommand("select PHONE from  reports.renewal_contact_t where run_date=to_date('+ d1 +','mm/dd/yyyy') and  EXP_DATE =to_date('07/21/2012','mm/dd/yyyy')", cn)

     ------------
     ada.Fill(ds, "reports.renewal_contact_t ")
    end try


    eror(in ada.fill statement)
     -----
    ORA-01858: a non-numeric character was found where a numeric was expected 