Button with text and image titanium alloy

I have done buttons with text and image in ios as well as android. In titanium alloy i added the image this way

<Button  class="span2 fblogin" onClick="fbLogin" top="70%" image="/images/global/Social_Sign_In_03.jpg" >Sign in with Facebook</Button>

I wanted to know whether this is the only way to add image to a button in titanium alloy or is there any other alternative? because i want to set the width height and the offset(left,right,top margins etc) on this image before adding it to the button. I am on 3.2.3 GA Thanks