How to solve problem with "NAN" in the report !

Hi all,

I have this expression in one of my report as a value for a textbox. Some times the value for the fileds used in this expression (Fields!Basic_Dollars.Value and Fields!Applied_Dollars.Value)  will have an empty string. So a "NAN" value is appearing in the report. How can I solve this problem please?

=Sum(Fields!Basic_Dollars.Value, "basicapplied") * 100/(Sum(Fields!Basic_Dollars.Value, "basicapplied") + Sum(Fields!Applied_Dollars.Value, "basicapplied"))

Thank you in advance.

Ephi