ユーザーエージェントによって読み込むスクリプトを変更する

これができるとイロイロと便利です。

<script type="text/javascript">
$(function(){
	var _ua = (function(){
	 return {
	  ltIE6:typeof window.addEventListener == "undefined" && typeof document.documentElement.style.maxHeight == "undefined",
	  ltIE7:typeof window.addEventListener == "undefined" && typeof document.querySelectorAll == "undefined",
	  ltIE8:typeof window.addEventListener == "undefined" && typeof document.getElementsByClassName == "undefined",
	  ltIE9:document.uniqueID && !window.matchMedia,
	  gtIE10:document.uniqueID && document.documentMode >= 10,
	  Trident:document.uniqueID,
	  Gecko:'MozAppearance' in document.documentElement.style,
	  Presto:window.opera,
	  Blink:window.chrome,
	  Webkit:!window.chrome && 'WebkitAppearance' in document.documentElement.style,
	  Touch:typeof document.ontouchstart != "undefined",
	  Mobile:typeof window.orientation != "undefined",
	  Pointer:window.navigator.pointerEnabled,
	  MSPoniter:window.navigator.msPointerEnabled
	 }
	})();
	
	function require(src){
	var element=document.createElement('script');
	element.type='text/javascript';
	element.src=src;
	document.getElementsByTagName('head')[0].appendChild(element);
	}
	
	if(_ua.ltIE8 || _ua.Gecko || _ua.Webkit){
		$('#wrapper').css("background","#000000");
		require('js/sample_ie.js');
	}else{
		require('js/sample.js');
	}
});
</script>

参考ページ
https://w3g.jp/blog/tools/js_browser_sniffing
http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1161871241