innerHTML, firefox, IE, and 'object error'

I am sure this has been answered before since someone surely has tried
this. Or I am doing it backwards....

I have a div that I am repopulating during an ajax callback. I'm
using prototype.js...

Example:

function showTags_handleResponse(originalRequest)
{
try
{
var elements = originalRequest.responseText.split("@");
var targetdiv = elements[0];
var targetdiv_thetext = elements[1];

var target_hdn = targetdiv+'_hdn';

$(target_hdn).innerHTML = targetdiv_thetext;


}
catch (err)
{
alert("showTags_handleResponse:"+err);
}

return;
}
--------------------------

$(target_hdn).innerHTML = targetdiv_thetext; <--throws the oh-so
descriptive 'object error' in IE, but works dandy in FireFox.

Any assistance would be greatly appreciated...I'll even take abuse if
I've done thing stupidly, as long as the abuse comes with the
assistance

Thanks.
-Devlon

Same thing going on here, almost exactly the same setup, using
prototype via ajaxCFC (cf ajax framework) and I am attempting to write
into innerHTML in the same fashion. Not sure I can be of much help
though I thought I'd ping in to see if you've found anything since
this post.

Any luck so far?