I have read many forums and answers on the Internet and since I will not be taking C#.NET at my university until later, I still want to know how to modify a textbox on my main form from another form. I am making an automatic code generator for HTML, and on my main form I have a textbox showing the HTML code currently in a .html file. On my main form, I also have a button to access a code editor, which I put into a different windows form. Now, whenever I make code changes in my code editor, save it, and exit that windows form, what do I write in that formClosing or formClosed event handler to update the textbox on my MAIN form? By the way, I have already set that textbox to public status.