Problem instantiating form classes created in other C# project

[C# Programming]

Does anybody know why I can't instantiate a form in my program.cs class. I'm developing a solution with multiple projects. Some are win form applications, some are class libraries and some are web applications. In this case i'm working with a win forms application. I have created forms in another project and I wish to add them to a the new win form project. Intellisense is not picking up the class names. I've also made sure that the forms use the correct namespace but with no success.

Help please!