The easiest way to set margins is in Layout->Document->Paper. If you need to
use the commands, then here are some stabs:
> In the User Guide, I found:
>
> setlength{hoffset}{-0.5 in}
>
> setlength{voffset}{-0.5 in}
Did you type setlength... or \setlength? Did you type voffset or did you type
\voffset?
> LaTeX Error: Missing \begin{document}.
> s
> etlength{voffset}{-0.5 in}
> You're in trouble here. Try typing <return> to proceed.
> If that doesn't work, type X <return> to quit.
Did you omit an '\' for \setlength in the preamble, and an '\' for \voffset?
>
> I also have tried
>
> \setlength{hoffset}{-0.5 in} - that gets the error dialog to not look
> as oddly but still does not help.
You would still need an '\' in the braces, as in {\hoffset}
Hope that helps... and welcom to LyX!
