Formula to Calculate weekdays in a month

I am having trouble coming up with a formula that will tell me how many weekdays there are in a month. I would need this formula to give me the number of weekdays in every month. Does anyone know how I would go about doing this? I have been struggling with this for 4 days now and ANY help would be GREATLY appreciated.

Thanks in advance.

Hi,

Try this download.

Click here

Is crystal Report is necessary installed for Vb.net.

Look at the help on the DateDiff function, specifically the last example.