Global cookie getter/setter

cookie.js

window.cookie = {
  set: function(cname, cvalue, exday){
    var d = new Date();
    d.setTime(d.getTime() + (exday*24*60*60*1000));
    var expires = "expires="+d.toUTCString();
    document.cookie = cname + "=" + cvalue + "; " + expires;
  },
  get : function(cname) {
    var name = cname + "=";
    var ca = document.cookie.split(';');
    for(var i=0; i<ca.length; i++) {
      var c = ca[i];
      while (c.charAt(0)==' ') c = c.substring(1);
      if (c.indexOf(name) == 0) return c.substring(name.length,c.length);
    }
    return "";
  },
  del: function(cname){
    return this.set(cname,"",-1);
  }
}