On page 31 of the thbook there is the very innocent line Use the revise command if you want to add maps from higher levels to the preview. This probably helps with one of my problems BUT Further reading of revise on pp33 revise’ Description: This command is used to set or change properties of an already existing object. Syntax: The syntax of this command for object created with “single line” command is revise id [-option1 value1 -option2 value2 ...] For objects created with “multi line” commands is syntax following revise id [-option1 value1 -option2 value2 ...] ... optionX valueX data ... endrevise Context: all Arguments: The id stands for object identifier (the id of an object you want to revise must always be specified). Sorry that is not getting me anywhere, could someone please give an example, preferably relating to the level of maps thanks Andrew PS I cannot get preview/offsets to work for projected elevations, should they, the thbooks seems to say any map!!