$text =~ s/$target/$replace/;
$text =~ s/$target2/$replace/;

##</code><code>##

$text =~ s/$target/$replace/i; # Case-insensitive

##</code><code>##

#!perl -i~ -p

BEGIN {
$/ = undef;
$target = blah blah blah;
$replace = blah blah blah;
}

s/$target/$replace/ig;

##</code><code>##

myprog.pl *.asp