"The most effective debugging tool is still careful thought, coupled with judiciously placed print statements."

Brian Kernighan, "Unix for Beginners" (1979)

Still true in 2015.

sub tryagain5 {
    my ($messagetouser) = @_;
    my $ans = callandresponse($messagetouser);
    my $count=1;

    # DEBUG
    print "ans is <<$ans>>\n";
    print "count is <<$count>>\n";

    while ($count < 5 and $ans =~ /^\s*\n/) {
        $count++;
        $ans = callandresponse ($messagetouser);
    }
    if ($ans =~ /^\s*\n/) {
        return 0;
    }
    else {
        return $ans;
    }
}
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You should learn how to indent your programs properly: use perltidy. Bad indentation (like yours) is a serious hindrance to careful thought.