How do I stretch popup message window

[FoxdenVixen]

I don't know if the window is really called that. It shows whenever certain popup text needs to show on your screen. Somehow, mine became smaller. I don't know if I clicked something that shrunk it or not. I need to figure out how to stretch it back out. It doesn't stay on my screen long enough for me to manually to this by hitting F10. An example is I enter our guild hall and there is a sign that pops up a message about on the house mending. It is cut off.