How do you scale lines once added?

I have a collection of lines that form a map. Basic green lines on screen. There area about 5000 lines to a map. I need to support zooming. Once added to the screen what is the best way to zoom in on the map? Do I need to remove them and edit the x1,y1,x2,y2 values or is there a way to change the display scale? Please keep in mind that I want to zoom in on the map, but do not want the thickness of the lines to increase.

Thanks,

Dave [import]uid: 18679 topic_id: 5212 reply_id: 305212[/import]