Problem finding datasource in accordion pane

Hi, I had difficulty in finding a datasource in an accordionPane.

To start off, i had an accordionPane and it contains 3 gridviews.
The first gridview(master gridview) has its datasource binded outside the accordion and the other 2 gridviews had their datasource within the accordion and databinded already.

The error i gotten is :The DataSourceID of 'basicBookDetails' must be the ID of a control of type IDataSource. A control with ID 'bookExtensionDataSource' could not be found.
basicBookDetails is the 2nd gridview and bookExtensionDataSource is the ID of the datasource that is already binded with the 2nd gridview within the accordionPane.

Can someone help me regarding this problem? Thanks.

In the page_load try a findcontrol as below:

YourAccordionPane.FindControl("bookExtensionDataSource");