I am using Visual Studio Pro and have built in a Crystal Report
that is viewed under my asp.net webpage.

Question : I need to be able to pass the report a parameter
from the webpage. How can I programatically add a variable to my report that can be set by the webpage that creates the report?

I want to format my report based on the value of this variable.

Chhers.

you can create a parameter in your report and set the value of this parameter through code using the SetParameterValue method of the ReportDocument Class

   ReportDocument cr = new ReportDocument();
   cr.Load(strReportPath);
   cr.SetDataSource(DS.Tables["Customers"]);
   cr.SetParameterValue("StartDate", strMyParmValue);
   CrystalReportViewer.ReportSource = cr;


Regards
Ganesh