Problem redering ajax retrieved variables

Problem redering ajax retrieved variables

To assign html code to a div I am using thefollowing:
 
$('#additionaloptions').html(vAdditionalOptions);
 
if vAdditionalOptions = "<font color='#FF0000'>Here is the red text</font>".
 
This does not render any html style tags <font color='#FF0000'></font> they are just included in the displayed text.
 
the following does work however
 
$('#additionaloptions').html("<font color='#FF0000'>Here is the red text</font>");
 
I am using   var vProductDetails = ParseXMLText("productdetails", xmlResponse);
 to retrieve the data.
 
I am not sure how to get the html code in the variable to be rendered.
 
Thanks.