error during deployment

Question

while deploying my project (C# codes) which includes Crystal report and crystal reportviewer,
iam getting an error during build solution
1)  "The type or namespace name 'CrystalReport1' could not be found(are you missing an assembly reference?)"

any one can tell me how to add directive or an assembly reference to project by step by step...(mention name of directive should be add)
need urgent