help about xml of streetmap

Hello! we’re developing a project for a university from Spain.First excuse us for our bad english. We have some problems.
we have a java aplication that it has an applet.we want to draw the map of openstreetmap on applet’s background.The problem is that we don’t know put the coordenates from xml to the image of the aplication.
Other problem is that we have seen that there are coordenates bigger than maxlon(=maxlat) and lower than minlon(=maxlon). We don`t understand because there are coordenates out of range.
we are waiting your answers.

Regards.

Thank you.