use of chart Engine in java application

mann

Hi,
I m new to BIRT Chart .
I want to create chart by using birt chart in my java Application.
I created on class wich hav function for creating pieChart
and one class which loads PNG driver and create png image file of that chart
I included all .jar files from chart Engine and requered files from Report Engine

But i m getting exception
this is the exception


Mar 31, 2008 4:24:58 PM org.eclipse.birt.chart.util.PluginSettings instance
WARNING: Exception
org.eclipse.birt.core.exception.BirtException: Cant startup the OSGI framework
at org.eclipse.birt.core.framework.Platform.startup(Platform.java:90)
at org.eclipse.birt.chart.util.PluginSettings.instance(PluginSettings.java:298)
at org.eclipse.birt.chart.util.PluginSettings.instance(PluginSettings.java:274)
at DataChartsViewer1.<init>(DataChartsViewer1.java:68)
at DataChartsViewer1.main(DataChartsViewer1.java:57)
Caused by: org.eclipse.birt.core.exception.BirtException: Could not find the Framework - org.eclipse.osgi
at org.eclipse.birt.core.framework.osgi.OSGILauncher.startup(OSGILauncher.java:95)
at org.eclipse.birt.core.framework.Platform.startup(Platform.java:78)
... 4 more


what shd I do??????
Is any more Api's are required?????????
please help me...........

thnks
mann