I have a new managed C++ Form project (my first) and if I try to declare a StreamReader object I get an error that I don't understand:

private: System::Void Form1_Load(System::Object^  sender, System::EventArgs^  e) {

		 StreamReader sr;
This generates an error on compiling:

error C3767: 'System::IO::StreamReader::StreamReader': candidate function(s) not accessible c:\my documents\visual studio 2008\projects\windowsforms\windowsforms\Form1.h

Can someone explain what this means please?