Comments are useful to remind you of something important in the program. To add a regular comment, place the cursor on any line in the disassembly listing, and press the hotkey colon (:), this will bring up the comment entry dialog where you can enter the comments. The following listing shows the comments (starting with ;) describing individual instructions:
.text:00401006 mov [ebp+x], 1 ; x = 1.text:0040100D mov eax, [ebp+x] ; eax = x.text:00401010 mov [ebp+y], eax ; y = eax.text:00401013 xor eax, eax ; return 0.text:00401018 retn
The regular comments are particularly useful for describing a single line (even though you can enter multiple lines), but it would be great if we could group the preceding comments together ...