Exhibit B

                             JOINT FILING AGREEMENT

         This Agreement is filed as an exhibit to Schedule 13G/A being filed by

Potomac Capital Management LLC, Potomac Capital Management II LLC, Potomac

Capital Management Inc., and Paul J. Solit in compliance with Rule 13d-1(k) of

the Securities and Exchange Commission, which requires an agreement in writing

indicating that the Schedule 13G/A to which this Agreement is attached is filed on

behalf of the below-named entities, that they are each responsible for the

timely filing of the Schedule 13G/A and any amendments thereto and for the

completeness and accuracy of the information concerning such persons contained

therein.

Dated: April 20, 2010

                                          POTOMAC CAPITAL MANAGEMENT LLC

                                          By:   /s/ Paul J. Solit

                                                --------------------------------

                                                Paul J. Solit, Managing Member

                                          POTOMAC CAPITAL MANAGEMENT II LLC

                                          By:   /s/ Paul J. Solit

                                                --------------------------------

                                                Paul J. Solit, Managing Member

                                          PAUL J. SOLIT

                                          By:   /s/ Paul J. Solit

                                                --------------------------------

                                                Paul J. Solit