This isn't about using IE conditionals, here is my problem
I have a fixed width site, I'm using 960 grid and I like this, and it works in most browsers including ie8 and ie7.
Now I like that old browsers like ie7 ie8 and use the 960 file fixed width and default style.css wordpress and modern browsers use the fluid version of 960 grid.
Summarizing
a) In old browsers load fixed width 960. b) In modern browsers use the fluid version of 960 responsive to the site.
Modern browsers can be detected and used a style sheet for them and in older browsers another style sheet?
Is there any function in wordpress that allows loading a stylesheet if the browser is modern, and load another stylesheet if the browser is old?