Mine is a mdi windows application.

i was already added that form in the required project in this way
  right click on project name->add->addexisting Item
          then i was selected that form from the location
       the form was added but i tried to use that form in my application in this way

private void menuItem7_Click(object sender, System.EventArgs e)
{
Form1 objfrm = new Form1();
}

but it gives error in this way
ERRors:-
            The type or namespace name 'Input' could not be found (are you missing a using directive or an assembly reference?)

 In addition to adding the form (Form1.cs, Form1.designer.cs , Form1.resx) i also added the exe file using add refernce... .
But still failed.

Thnks in advance.

I think the error pretty much says it all.

There is a variable in your imported Form1 that uses a type that is not declared. e.g.

Input i = new Input();

If you double click on the error it should take you to the line where the error is caused.

If you load up the form in the original project and then hover over the same line it should tell you what namespace Input is taken from (e.g. System.Security.Input or whatever). This might be a custom control or some other third party DLL.

Then you just need to add a reference to that DLL to your current project.

/- Sam Judson : Wrox Technical Editor -/