i am using google bar chart for representing data for ma web application.but it works properly only if i am running the application for the very first time by opening a browser...if i try for a second time by keeping my first browser window open..i am not getting the new chart corresponding to new values..it just loading the old graph(chart) again as if from a cache....
any help is appreciated..
thanks in advance!!!

If the chart has new values, the URL will be different and the image won't be cached.

Are you by any chance saving the images yourself on your own server?

Are you trying to replace the first image with the second or are you trying to render them both together?

You say:
"if i try for a second time by keeping my first browser window open ..."

Is the second try in the same browser window?

Are you generating the chart url with javascript? An error in your javascript code could prevent the url from being generated or the image from being replaced. Have the javascript print the url along with loading it. You can then see what is happening.

Can you provide the urls here for us to try?