Help Saving Settings?

Question

OK, I have a program that creates a variable, displays that variable in a textbox, the user uses buttons to edit the variables content, and when the form closes, I use the Properties.Settings.Default.Setting hoping when I pull up the form again, the Setting will be put into the value of the variable (How I have it programmed to do) go into the textbox for user input to edit, and when I'm done it saves it to start all over.

But it doesn't.  It doesn't show any errors, it just doesn't save for the next time I use it.

What's the best way to do this?  What am I doing wrong?