Inject css

injectStyle.js

$('head #missionStyles').remove();
var css_href = "some/path/to.css";
if (document.createStyleSheet) {
  var $link = $("<link>");
  $link.appendTo($('head'))
    .attr('id', 'missionStyles')
    .attr({type : 'text/css', rel : 'stylesheet'})
    .attr('href', css_href);
} else {
  $('head').append("<link id='missionStyles' rel='stylesheet' href='"+css_href+"' >");
}