C# "invalid Expression" error

            {
                A = 1
                if ( [COLOR="Red"]==[/COLOR] null) (This is the error)
                    com.ms.vjsharp.lang.ObjectImpl.getClass();
                A = 1
                C = 3
                B = 2
                b = 5
                A = 1
                a = 4
                A = 1
                A.A.insertElementAt((new java.lang.StringBuffer()).append().append(" \uFFFD").append().ToString(), 0);
                if (A.A.size() > 1000)
                    A.A.removeElementAt(1000);
                A.B = true;
                start();
            }