This code works awesome in IE, but won't work in NS6?

can someone give advice?

Code:
<a href="#"><span style="width:97%">Test Button 1</span><span style="width:3%"><img width="4" height="7" alt="" border="0" src="mnuArrow.gif"></span></a>
What happens is that in IE the image is aligned to the right, but in NS6 it is not.