IO540 strangely enough it was mentioned by someone else who found it, in a post on the first page of this topic, but I am more than happy to include it again:
Airtime Charters - Complete ALL details as you would with a paper GAR then click SUBMIT GAR FORM at the bottom of the page | Airtime Charters
Although an IT/Web developer myself (yes I hear the cries of traitor!) I do appreciate the need for a simple online GAR submission form that does just that.