Does anybody know how to get the best acoustics in a school hall?

Hi, our band is playing in our school embly on friday, we consist of two guitarists, a bist, a singer and a drummer using basic amplifiers, nothing special. The sound acoustics in the room are pretty bad, it echoes too much and we are not on a stage so the sound we produce will be absorbed quickly within the first few rows of people. Does anybody know how to get the best sound so the audience will hear us better and enjoy it more, the hall isn't extremely big. Please try and answer before the the 19th of January 2007. Thanks very much, hope to hear from you soon.