How to effectively Negotiate Wage

My title at the company I work at is Technical Support Specialist. I maintain a windows 2000 server environment. I use exchange for email. I manage and maintain all workstations and anything that has to do with the servers (set up dns,dhcp,eschange system manager,symantec system console,AD,group policy). I have a degree in Computer Network Systems. I am currently studying for the MCSE 2003 tests and CCNA test. I basically do any and everything PC and Server related for this company. I am making $14.00 hour. I am negotiating wage with VP of company and he fills I am making more than I am worth. How do I prove that I should be getting more than he is paying me? Any advice would be great, thanks.