[SOLVED] The name xyz does not exist in the current context. I know why it happens but can't fix.

Question

I have a simple form with a textbox.

When the user hits '1' the textbox should display '1'.

But let's look inside the program:

Normally, I could do something like: setText("1");

But since I'm trying to incorporate OOP principles, I should be doing something more like: ghostClass.setText("1");

setText() basically does this -> theTextBox.Text = textToSet;

Yes, without OOP, that'd work. But with OOP, the ghostClass shouldn't even know theTextBox exists right? So it can't do this -> theTextBox.Text = textToSet; <- because this -> The name 'theTextBox' does not exist in the current context. <- would happen.

I was thinking that instead of -> setText("1") <- I should be using somethign clsoer to -> theTextBox.Text = ghostClass.setText("1"); <- but when I look at that I feel it should just say -> theTextBox.Text = "1"; <- and that I have unnecssary complicated the code--I mean why would I sent the text to set only to have it returned? -_-

I could eleborate on the issue even more by introducing another method -> ghostClass.clearTextBox(); As before I can't use -> theTextBox.Text = string.Empty <- because of the existence issue.

Please help.