I have object tag that look like this :
\" id=\"embedde
First of all the c:url
tag has nothing to do with the browser-side behavior. The tag should be rewritten by server and the browser should receive an absolute path. (Maybe you can post source from your browser?)
So the problem is only the browser compatibility of PDF embed in . Most modern browsers should work with this tag including Firefox, so you should check whether you have pdf plugin properly installed on your Firefox.
For the IE problem you didn't mention which version you are using, so it may be solved by using other than
to solve this problem. According to this answer, you may try this style for better compatibility: