use strict;
use warnings;

my $fileText;
do {local $/; $fileText = <DATA>};

my $rxOK = qr
   {(?xms)
      ^First\sName
      (?=.*?^Last\sName)
   };

print
   $fileText =~ $rxOK
   ? qq{File OK\n}
   : qq{File BAD\n};

__END__
.....
First Name
.....
.....
Last Name
.....