Which language?

Im trying to build a management software that is installed on an employees computer and communicates with a website.

*i wish i knew the terminology*

i want the employee to do most of the work on the program, and then i want the program to sync with the wesite.

i am intermediate at php
intermediate at actionscript

my question is:

which language would be best for this?

a lot of combination there, php + mySql + javascript or other html script(for interface). I think that combination cover everything we need.