well hi to all seniors in the forum

im new at making dvds and i just found out winavi .... i have some rmvb files that play fine (video and sound clear)

problem arises when i convert them to dvd...... after converting the video is still the same (just a bit lower in quality)  but there is absolutely no sound at all throughout the whole video....

what is causing this problem?

hope some seniors can help me out on this