My boss however, wanted me to look into something advanced regarding charting and I saw that it was not possible with the out-of-the-box charts that Flex provided. So I started to google for alternatives and found that some people have created additional charting components that are really great. I have included a couple of them here:
Funny thing as well this week I attended an online demo of BIRT, which actually uses Flex to draw it's charts. So take a look at the links above and enjoy :)