IsNan() function

Hi All,

I would like to ask regarding the IsNan() function. How is it used and what is its output?
I am using it in an if statement and cant seem to get a result. It only outputs #error in my report.
I am using it in a matrix report which displays the percentage(%) calculation for project hours of a department.
There might be where a department has no project hours clocked and I would like to output 0%

Can anyone help?

Thanks & Regards,
Fadzli