<title>My Example</title>
<marquee behavior="scroll" direction="left" scrollamount="6" id="mymarquee">
<p>Go on... press the button!</p>
<input type="button" value="Slower" onClick="document.getElementById('mymarquee').setAttribute('scrollamount', 1, 0);">
<input type="button" value="Normal Speed" onClick="document.getElementById('mymarquee').setAttribute('scrollamount', 6, 0);">
<input type="button" value="Faster" onClick="document.getElementById('mymarquee').setAttribute('scrollamount', 12, 0);">