is separate from the
statement - the
tells the system what assembly files to include, while the
is a "syntactic sugar" which lets you write
and then use
MyClass mc = new MyClass();
Instead of having to write the full name each time:
MyAssembly.MyClass mc = new MyAssembly.MyClass();
Until you have added the reference, you can't use either form.
To add it, open the Solution Explorer pane, and open your project branch.
Right click the "References" branch, and select "Add reference..." use the dialog to locate the assembly - there are a number of ways you can do this depending on where the assembly file is - and tick the check box. In your case, it's probably MyApp.exe or MyApp.dll
Press OK to add the reference to the project.