I get a cookie in js like this:

alert(this.getCookie('userName'));

cn.url+='?name='+this.getCookie('userName');

alert(this.getCookie('userName'));

document.writeln(cn.url);

When the first alert, the output is "%B6%A6%CC%EC" ;
and the next alert,the output is right,
but when the doucument created, the document output like this:

http://x.x.x.x/bbs.jsp?name= ¶¦Ìì

why this happens,I need help.