动态创建css节点

function addCssDynamic(css){
if(navigator.userAgent.indexOf("MSIE 6.0") != -1){ 
window.style = css; 
document.createStyleSheet("javascript:style"); 
}else{
try{
var style = document.createElement('style'); 
style.type = 'text/css'; 
style.innerHTML = css; 
document.getElementsByTagName('HEAD').item(0).appendChild(style); 
}catch(e){
var sheet = document.createStyleSheet(); 
var css_sel = css.split("}");
for(var sel in css_sel){
if(!css_sel[sel])continue;
var sel_arr = css_sel[sel].split("{");
sheet.addRule(sel_arr[0], sel_arr[1]);
} 
}


} 
}