$grey = $gd->colorAllocate(220,220,220);
@list = $dia->get_hotspot(1,$point);
$gd->dashedLine($list[1],25,$list[1],$list[2],$grey);

##</code><code>##

Can't use an undefined value as an ARRAY reference at /usr/local/lib/perl5/site_perl/5.6.1/GD/Graph/axestype.pm line 366.