if (eval "require LWP::UserAgent; 1") {

	my %post = ('key' => 'value');
	my $ua = LWP::UserAgent->new();

	my $content = $ua->post("http://www.mydomain/post.cgi",[%post])->as_string;

	#do something with the content ...
} else {
	print "LWP not available";
}