Hi Hasvi,
Use the below links to get more knowledge:
Font Status:
http://jongware.mit.edu/idcs5js_html_3.0.3i/idcs5js/pe_FontStatus.html
Links:
http://my.safaribooksonline.com/book/graphic-design/0321409698/javascript-reference/ch03le v1sec190
Regards
Siraj