Using UltraDev with Phakt can't connect to mysql server!

Dear Sir I had installed phakt into my Ultradev, but when i modify the connect of the database on mysql, it prompts me the message as follow: "org/git/mm/mysql/driver" "Class not found", could you tell me what is the most likely is? I had try to use my computer to connect to the mysql in my server, it works! but i couldn't do it inside ultradev. I had set the application server to PHP4 already and the os which containing the MYSQL Server is Windows NT server 4.0 with service pack 5! Is there anything i got to download to fix this problem!! I'm working this for my company's project, so could you pls send tell to me?? thx jack jack@nedcor.com