Samsung orange slider a737 has

Question

this morning my cellphone started repeating the on/off cycle and then it ended up with a dark blue screen with nothing on it except an orange band saying "download" on it. i tried doing the on/off cycle but the buttons wouldn't affect it. then i took out the battery and the sim card for a few minutes and when i put them back in the same screen comes up????
it won't reboot or do anything, please advise.