I hv a error msg when export to others format.

'++++++++++++++++++++++++++++++++++++++++++
Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the
current web request. Please review the stack trace for more information
about the error and where it originated in the code.

Exception Details: System.NullReferenceException: Object reference not set
to an instance of an object.

Source Error: Error Line 143

Line 142:        crDiskFileDestinationOptions = New
DiskFileDestinationOptions()
Line 143:        crExportOptions = crReportDocument.ExportOptions
'++++++++++++++++++++++++++++++++++++++++++++++

Can someone help.

Thanks in advanced.

rgds,
phoebe.