I dont know why this error arise

Question

Hi,
Can somebody tell me why m facing this problem when I define a method for calculating the route in Bingmap in Windows Phone7.
The line of code is :

     routeLine.Locations.Add(new Location(p.Latitude, p.Longitude));

the error I get is : 

Error1:'Microsoft.Phone.Controls.Maps.Platform.Location' does not contain a constructor that takes 2 arguments