js操作cookie

function createCookie(){
	//a是cookie名,obj是cookie值
	var cookievalue="1,5,8";
   cCookie(cookievalue);
}

function cCookie(cookievalue){
   document.cookie=cookiename+"="+cookievalue+";";
}


function getCookieVal(offset)
{
 var endstr = document.cookie.indexOf(";", offset);
 if(endstr == -1){
  endstr = document.cookie.length;
 }
 return unescape(document.cookie.substring(offset, endstr));
}


function getCookie(name)//读cookie
{
 var arg = name + "=";
 var alen = arg.length;
 var clen = document.cookie.length;
 var i = 0;
 while(i < clen){
  var j = i + alen;
  if (document.cookie.substring(i, j) == arg){
  return getCookieVal(j);
  }
  i = document.cookie.indexOf(" ", i) + 1;
  if(i == 0) break;
 }
 return;
} 

function settextValue(){

  var v=getCookie(cookiename);
  var txt = document.getElementById("txt");
  txt.value=v;
}
function delCookie(sName){// 删除 cookie
  var date = new Date();
  document.cookie = sName + "= ; expires=" + date.toGMTString();
}