Exhibit A

Identification of entities which acquired the shares which are the subject of
this report on Schedule 13G/A.

(1)      Potomac Capital Partners LP, a private investment partnership formed
         under the laws of State of Delaware. Potomac Capital Management LLC is
         the General Partner of Potomac Capital Partners LP. Mr. Paul J. Solit
         is the Managing Member of Potomac Capital Management LLC.

(2)      Potomac Capital International Ltd., an international business company
         formed under the laws of the British Virgin Islands. Potomac Capital
         Management Inc. is the Investment Manager of Potomac Capital
         International Ltd. Paul J. Solit is the President and sole owner of
         Potomac Capital Management Inc., and a Director of Potomac Capital
         International Ltd.

(3)      Pleiades Investment Partners-R, LP, a private investment partnership
         formed under the laws of the State of Delaware. Potomac Capital
         Management Inc. is the Investment Manager of a managed account of
         Pleiades Investment Partners-R, LP. Paul J. Solit is the President and
         sole owner of Potomac Capital Management Inc.