Thanks guys but i have decided that the best way for my script to identify me is even simpler that using cookies.... here it is....

if ($host =~ /thes530-.*?\.otenet\.gr|millennium-.*?\.ccf\.auth\.gr/)
[download]

Although my ip from the two providers i use is dynamic this solution works just fine for me :)

The cookies solution can alsobe done but it wouldn't be as quick and short as this one :)