I'm trying to make some kind of graphical representation of some values.

In my draw method, i'm calling line(), and everything works ok - all values are shown on screen as nice graph streching from left to right.

However, i want to display numerical data too using text(). If i display it, characters do not refresh themselves.
If i reset background in the beginning of draw (), numbers do reset, but my lines reset to :)

So, is it possible to define one graphical element as object and manipulate with it (delete it), or there is some other way to do this?