> whats the apply button for? Really only for setting the contours to the manually defined levels in the lower entry. (This is in the documentation) Maybe it is not totally clear. However, there is a tricky situation here in that the manual levels change the auto levels (if appropriate) and the auto levels change the manual levels entry. T. ------------------------------------------------------------------------------- Dr Tim Stevens Email: [log in to unmask] Department of Biochemistry [log in to unmask] University of Cambridge Phone: +44 1223 766022 (office) 80 Tennis Court Road +44 7816 338275 (mobile) Old Addenbrooke's Site +44 1223 364613 (home) Cambridge CB2 1GA WWWeb: http://www.bio.cam.ac.uk/~tjs23 United Kingdom http://www.pantonia.co.uk ------------------------------------------------------------------------------- ------ +NH3CH(CH(CH3)OH)C(O)NHCH(CH(CH3)CH2CH3)C(O)NHCH(CH2CH2SCH3)CO2- ------- -------------------------------------------------------------------------------