cannot find the datasource in struts?

[Manish Pandya]

a newbie in using struts...
kindly let me know what i should be doing to define a datasource..
i have the struts-config.xml file where i defined the datasource
parameters...
and now i m trying to run the example provided in the struts....
but it is throwing error javax.sql.DataSource not found...

is there anything that i m missing? let me know please...