"AD\thomas"  -> "AD    homas" # tab
"MAIN\nancy" -> "MAIN         
                 ancy"        # newline
"nancy"      -> "nancy"       # no domain, no problem

##</code><code>##

$domainID =~ (s/(AD|MAIN)\n/n/);   # should not be
$domainID =~ (s/(AD|MAIN)\r/r/);   # checked 3 times
$domainID =~ (s/(AD|MAIN)\t/t/);   # before exiting

##</code><code>##

our %whitespace = ( "\f" => "f","\n" => "n","\r" => "r","\t" => "t" );

$netid =~ (s/(\s)/$whitespace{$1}/g);
$netid =~ (s/(AD|MAIN)//);

##</code><code>##

"AD\thomas"  -> "thomas"
"MAIN\floyd" -> "floyd"
"AD\manny"   -> "manny" # perl escapes normal char, no harm