Internet Explorer Reformatting

Hello, I am building a site and I am starting to notice a lot of bugs, but the one that was brought to my attention that seems immediate attention is the word wrap in internet explorer. Firefox is a little off but acceptable at the moment. I am sure when I figure how to reformat internet explorer i will optimize firefox. My question is how do you set up a string of code that will detect a browser and allow me to reformat the page. Thank you very much.