Okay, I now have worked out how to change the innerHTML but the control remains the same ... is there a way to redraw / refresh it? Here is the code so far.
lp = document.getElementById('CE_ctl00_ctl01_bcr_PostForm___PostBody___Editor_IDfontname');
if(lp)
{
lp.childNodes.item(0).removeAttribute('selected')
lp.childNodes.item(4).setAttribute('selected','True')
????????
}