I was watching this video http://channel9.msdn.com/Series/Mango-Jump-Start/Mango-Jump-Start-03-Silverlight-on-Windows-PhoneAdvanced , the 3rd in the series of mango jump start. I then downloaded the code for this. However when I try and open wazup.cs project in Visual studio 2010 express edition for windows phone it throws an error saying

 Unable to read the project file 'Wazup.csproj'