function createMyStyle(selector , rule) {
   j$("head").append('<style type="text/css">' + selector + '{' + rule + '}' + '</style>');
}

if( stylesheet.addRule ) {
    stylesheet.addRule(selector, rule);
}
else if( stylesheet.insertRule ) {
    stylesheet.insertRule(selector + ' { ' + rule + ' }', stylesheet.cssRules.length);
}

for( var i in document.styleSheets ) {
    if( !document.styleSheets[i].id) {

if($("style").length > 0){
  // this means you have a style  element in your document
}

$('head').append('<style id="some-id"> ... </style>');

console.log($('#some-id'));