How to assign dataset values to a parameter in Visual Studio 2008

Question

In Visual Studio 2005, a report parameter can be assigned a value from a dataset.fieldname.  The parameter value will change for each row and thus can be used in the report header as needed.  In my case, I use the parameter value to change an image based on the value in each row.  I do not see the same options to assign a dataset.fieldname to a report parameter in Visual Studio 2008.  Can it be done?  If so, how?

Thanks