C++ : Appending text in form

I've been away from C++ for a while and it may just be me being stupid, but why does this give me an error (error below code).

Code:

// NetworkServer.cpp : main project file.

#include "stdafx.h"
#include "Form1.h"
#include <winsock2.h>
#include <iostream>
using namespace std;
using namespace NetworkServer;

[STAThreadAttribute]
int main(array<System::String ^> ^args)
{
// Enabling Windows XP visual effects before any controls are created
Application::EnableVisualStyles();
Application::SetCompatibleTextRenderingDefault(false); 

// Create the main window and run it
Application::Run(gcnew Form1());


    public void setUsers()
{
    string connectedUsers[] = {"John", "Alex", "Phillip", "Steve"};
    Form1->txt_connectedClients.AppendText(connectedUsers[1]);
}

    return 0;
}

Error:

    1>NetworkServer.cpp(22): error C2143: syntax error : missing ';' before '->'
    1>NetworkServer.cpp(22): error C2143: syntax error : missing ';' before '->'

Form1 is a type name, you need an object. I can't see the context of the code but as long as this code is written inside a method of the Form1 class then this-> will work.

public ref class Form1 : public System::Windows::Forms::Form
{
   //...
public:
    void setUsers() {
        array<String^>^ connectedUsers = gcnew array<String^> {"John", "Alex", "Phillip", "Steve"};
        this->txt_connectedClients->AppendText(connectedUsers[1]);
    }
};

Beware that you're programming in the C++/CLI language, not C++.

Either txt_connectedClients doesn't exist or isn't a pointer. Try the dot operator instead.