The disabled attribute is not supported in IE, prior version 8 for HTML <option> disabled Attribute. http://www.w3schools.com/tags/att_option_disabled.asp
What options do we have to customize the look and make the field read only?
Warning!
Read the question twice, as we don’t ask about <input disabled> we ask about <option disabled>
This is entirely untrue.
Even IE7 dims an
<option disabled>element and prevents selecting it (IE6 however doesn’t).