My problem was this: i wanted to put bold on text which was in select's option by putting style - wont-weight. I had succeed only on Firefox. Because chrome user agent stylesheet were overriding my stylesheet.
I tried to solve the problem for hours. Finally with my friend's help i found the website - electrictoolbox. And it says that only firefox allows to do that... that means we cant use wont-weight on chrome for option, select and optgroup.
My solution was for the bold text changing wont-weight style into color, with dark color for normal text and lighter color for bold required. Also i needed disabling option of bold, so i just added " disabled='disabled' ". That is all..