C# Cannot inplicitly convert form to from : So i am trying to store my main form and open a new one however i get this error, here is the code:

I have this at form level

         public static frmAddBook frmkeepBooks = null;

         public frmMain()
        {
            InitializeComponent();
            frmkeepBooks = this;
        }
The error underlines "this" saying it "Cannot inplicitly convert type Books.frmMain to Books.frmAddBook"

    

