could anyone help me ? I need to create a window as a form in Visual COBOL .NET and then create a listview object into this form but from the listview class written in simple native code. So after creation of the form I need to call native code with the handle of the form and here's the problem. First time I use the form handle in the native code as a parameter in calling Windows API functions causes exception and the process is terminated. I was looking for the solution and I've found that perhaps something like SuppressUnmanagedCodeSecurity attribute must be specified in the calling managed code. But I don't know if I'm right and if I'm how to declare it. In the attachment file is dialog-box with the exception thrown by first calling Windows API with the form handle.