The following are the operators you can use with the IF, WHILE and DOCASE commands (all comparison are case-sensitive unless stated otherwise) : EQUAL (Insensitive) == (Comparison is CASE-INSENSITIVE) EQUAL (Sensitive) = (Comparison is CASE-SENSITIVE) NOT EQUAL != MORE > (Left side more than right side) MORE than or EQUAL to >= LESS < (Left side less than right side) LESS than or EQUAL to <= FILE HEADER COMPARE H= This operator MUST have a file name on the left of it and a comparison string on the right : IF df0:MyFile H= "FORM????ILBM" the comparison string contains the starting bytes of the file type you are looking for. - Question marks are wild (-see below-) STRING COMPARISON S= This MUST have a string on either side of it and will compare them. it is case-insensitive and wild characters can be used (see below). ex : IF "This" S= "THIS" This is meant to be used along with the ReadVar command and provides a faster method of checking file headers than the above H= operator. DEVICE COMPARISON D= FILE/DIR COMPARISON F= Both of these need a file, dir or device on either side. D= will yield TRUE if the files/dirs are on the same device, and F= will be TRUE if they are the same file or directory. Wild Characters that can be used with H= and S= ? Means any character # Means any Printable character % Means any UnPrintable character Operators MUST have a space to each side of them : if This= That <- is not correct if This=That <- is not correct if This = That <- is correct