I have to find a code for a banner effect in js, like this

a marquee -like effect.
I don't know any js.
I found something in the net but , while it works if is the only code in the page, when I put the code in the complex page, plenty of html ,it messed up all things, no matter when I place it ( in the head , in the body..) , the links disappeared.. a mess.

I need a working code for the banner: many of you are real programmers, help me with some tips.