CSS Include in Javascript!

CSSinJs

function include(urlLibrary, callback)
{
  var customLibraries = {
    "angularjs": {url: "//ajax.googleapis.com/ajax/libs/angularjs/1.2.15/angular.min.js"},
    "dojo": {url: "//ajax.googleapis.com/ajax/libs/dojo/1.9.3/dojo/dojo.js"},
    "ext core": {url: "//ajax.googleapis.com/ajax/libs/ext-core/3.1.0/ext-core.js"},
    "jquery": {url: "//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"},
    "jquery mobile": {url: "//ajax.googleapis.com/ajax/libs/jquerymobile/1.4.2/jquery.mobile.min.js", 
                      css: "//ajax.googleapis.com/ajax/libs/jquerymobile/1.4.2/jquery.mobile.min.css"},
    "jquery ui": {url: "//ajax.googleapis.com/ajax/libs/jqueryui/1.10.4/jquery-ui.min.js",
                 css: "//ajax.googleapis.com/ajax/libs/jqueryui/1.10.4/themes/smoothness/jquery-ui.css"},
    "mootools": {url: "//ajax.googleapis.com/ajax/libs/mootools/1.4.5/mootools-yui-compressed.js"},
    "protoype": {url: "//ajax.googleapis.com/ajax/libs/prototype/1.7.2.0/prototype.js"},
    "script.aculo.us": {url: "//ajax.googleapis.com/ajax/libs/scriptaculous/1.9.0/scriptaculous.js"},
    "swfobject": {url: "//ajax.googleapis.com/ajax/libs/swfobject/2.2/swfobject.js"},
    "web font loader": {url: "//ajax.googleapis.com/ajax/libs/webfont/1.5.3/webfont.js"},
    "paperjs": {url: "http://paperjs.org/assets/js/paper.js"},
    "codemirror": {url: "http://paperjs.org/assets/js/codemirror.js"},
    "cutjs": {url: "http://paperjs.org/assets/js/codemirror.js"},
    "p2js": {url: "http://schteppe.github.io/p2.js/build/p2.js"}
  };
  var finishUrl = null, finishUrlCss = null;
  if(customLibraries.propertyIsEnumerable(urlLibrary))
  {
    finishUrl = customLibraries[urlLibrary].url;
    if(customLibraries[urlLibrary].css !== null) finishUrlCss = customLibraries[urlLibrary].css;
  }
  else
  {
    var expression = /[-a-zA-Z0-9@:%_\+.~#?&//=]{2,256}\.[a-z]{2,4}\b(\/[-a-zA-Z0-9@:%_\+.~#?&//=]*)?/gi;
    var regex = new RegExp(expression);
    if(regex.exec(urlLibrary))
    {
      finishUrl = urlLibrary;
    }
    else
      console.error("This is an invalid Url or doesn't exist in the default libraries");
  }
  
  if(finishUrl !== null)
  {
    var js = document.createElement("script");
    js.type = "text/javascript";
    js.src = finishUrl;
    document.head.appendChild(js);
    
    if(finishUrlCss !== null)
    {
      var link = document.createElement("link");
      link.rel = "stylesheet";
      link.type = "text/css";
      link.href = finishUrlCss;
      document.head.appendChild(link);
    }
    js.onload = callback;
  }
}

use async script tag for better performance