Displaying Graphs in web page

Hi
What are the various options available to display dynamic graphs / charts in webpages?
Applets are one way to do it.
Another way is to generate image files in Servlets and display that image in HTML pages.
Are there any other way(s) to acheive this.
What are the advantages & dis-advantages of the various approachs?
If the graphs can provide drill-down features, it will be an added advantage

Thanks in advance.

with javascript, you will be only able to bar graphs easily.
It would just be done with tables, If you want an example, I could make one up. I could make it dynamic too.

Bars and columns can be done by stretching 1x1 pixel images, you don't even need Javascript.

Thanks for the replies.
But what are the options available if I want to display other type for charts (pie chart for example). And what about the drill-down features (the user has to click a particular part of the graph to get more detail on that info)?

You'd be able to do it better with third party libraries like - JFreeChart (too good), you can use it either with your applets or servlets.
http://www.jfree.org/jfreechart/index.html
- Manish