Help Wrong rom, dont access download mode

[Duukkee]

Hi, i "installed" a I9000 rom on galaxy vibrant, and this happened, starts in recovery mod but i cant chose the option reboot because galaxy vibrant dont have "ok" button and i cant put the download mode for odin recovery cuz the "ok" button.

how can i enter in download mode for odin? i want to return to stock rom but i cant enter download mode.

Thanks, sorry for my bad english.