How to do Conditional Formatting?

Hello,

I'd like to know how conditional formatting could be handled in Lout.
Here's some Psuedo C code that demonstrates what I'm after:

if ( canFitOnTheCurrentPage( text ) )
     print( text );
else {
     print( "See attached page" );
     newLine( );
     print( slightlyDifferentText );
}

I have an inkling of how I might be able to accomplish this with a
cross-reference symbol and a two-pass run but if someone with experience
could give me some advice I'd much appreciate it.

Regards,
Michael Koehmstedt