get nth weekday of month in C#

Possible Duplicate:
How do I determine if a given date is Nth weekday of the month?

How do i get the nth weekday of the month?

For ex.:

2nd Monday of "July 2010" = 07/12/2010.

Looking for a function like:

public DateTime GetNthWeekofMonth(DateTime date, int nthWeek, DayOfWeek dayofWeek)
{
//return the date of nth week of month
}

from the above, the parameters of the function will be ("Any Date in July 2010", 2, Monday).