EXHIBIT 1 JOINT FILING AGREEMENT The undersigned hereby agree to the joint filing of the Schedule 13G to which this Agreement is attached. Dated: February 26, 2004 OBERWEIS ASSET MANAGEMENT, INC.

                                                                       EXHIBIT 1

                             JOINT FILING AGREEMENT

         The undersigned hereby agree to the joint filing of the Schedule 13G to
which this Agreement is attached.

    Dated:  February 26, 2004

                                              OBERWEIS ASSET MANAGEMENT, INC.


                                              By:  /s/ Xxxxxxx X. Xxxxx
                                                   -----------------------------
                                                       Xxxxxxx X. Xxxxx
                                                       Executive Vice President

                                                   XXXXX X. XXXXXXXX

                                                   /s/ Xxxxx X. Xxxxxxxx
                                                   -----------------------------

                                                   XXXXX X. XXXXXXXX

                                                   /s/ Xxxxx X. Xxxxxxxx
                                                   -----------------------------