Simple newbie question for VBA

I'm using VBA wuth Excel and have a loop running which scans through data and plots it on a chart (like a dynamic graph).

When I pres escape it come up with the 'Debug' error asking if I wish to Debug or End (the one that also comes up when you press Ctrl+Break).

What I would like instead is to be able to simply exit the routine when the escape button is pressed. How do I do this?

I gather that I'll need a line which checks to see if a keyb input is received, but the help feature is useless for lettnig me know http://dev.www.sharkyforums.forums.relay.cool/.

The code would look something like this:
For i=1 to [...].count
[code line1]
[code line2]
['if Esc is pressed'] then Exit Sub
Next i

(anything in square brackets is obviously not code https://www.sharkyforums.com/images/.../2005/08/2.gif)

Thanks

------------------
Athlon TB 800MHz
Abit KT7a-RAID
250W PSU, Enlight Case
512MB PC133 SDRAM
30.7GB IBM Deskstar 7200RPM
32MB Diamond Viper770 Riva TNT2
Yamaha 6416 CDRW (SCSI)
16x Pioneer 106s DVD-ROM
52x LG Electronics CDROM
SB Live! 1024
Creative FPS1000 Speakers