function setActiveStyleSheet(myDocument, title) {
    var i, a, main;
    // Change stylesheet
    for(i=0; (a = myDocument.getElementsByTagName("link")[i]); i++) {
        if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title")) {
          a.disabled = true;
          if(a.getAttribute("title") == title) a.disabled = false;
        }
    }
}

function getActiveStyleSheet(myDocument) {
  var i, a;
  for(i=0; (a = myDocument.getElementsByTagName("link")[i]); i++) {
    if(a.getAttribute("rel").indexOf("style") != -1 && a.getAttribute("title") && !a.disabled) return a.getAttribute("title");
  }
  return getPreferredStyleSheet();
}

function getPreferredStyleSheet() {
  return '1024';
}

setActiveStyleSheet(document, getPreferredStyleSheet());