[idvusers] overlays - isl

Hi,
 
How do i add an overlay to a image in isl. I have read though the
manuel, but can't get it to work.
 
Below is the script i would like to add it to
 
 <?xml version="1.0" encoding="ISO-8859-1"?>
<isl debug="true" loop="1" offscreen="true" sleep="60.0minutes">
<bundle clear="true" file="${islpath}/MSLP_06_GFS.xidv" wait="true"
width="500" height="420"/> 
  <image file="C:\MODELGFS05_GRIB2\DATA\UK\IMAGES\MSLP_06_GFS.png"/>
</isl>
 
 
Thanks
Ian