Jdownloader error message on Windows

Installed JDownloader recently on my Windows XP SP 3 machine. I received a pop up telling there were 20 updates and I initiated to download all the updates.
To my surprise I saw that it just started a downloaded and some error message popped up and the download window got closed. Now I try to reopen it and it comes up with an error message to update Java version on my PC.
Failed Update detected! It seems that the previous web update failed. Please ensure that your java-version is equal-or above 1.5. More infos at http://www.syncom.org/projects/jdownloader/wiki/FAQ.
Java version on my machine is 1.5 and I am not sure which version should I update for this.
Please help.
