Javascript: Cookie Management

cookies.js

/**
 * determine whether this is the first visit to the animation page
 * @param  {string} c_name cookie name
 * @return {string}        cookie value
 */
function getCookie(c_name){
  var c_value = document.cookie;
  var c_start = c_value.indexOf(" " + c_name + "=");
  if (c_start === -1){
    c_start = c_value.indexOf(c_name + "=");
  }
  if (c_start === -1){
    c_value = null;
  }
  else{
    c_start = c_value.indexOf("=", c_start) + 1;
    var c_end = c_value.indexOf(";", c_start);
    if (c_end === -1){
      c_end = c_value.length;
    }
    c_value = unescape(c_value.substring(c_start,c_end));
  }
  return c_value;
}
/**
 * Sets a cookie determining action for the next animation view
 * @param {string} c_name cookie name
 * @param {string} value  the value to be set
 * @param {int} exdays days until expiry
 */
function setCookie(c_name,value,exdays){
  var exdate=new Date();
  exdate.setDate(exdate.getDate() + exdays);
  var c_value=escape(value) + ((exdays===null) ? "" : "; expires="+exdate.toUTCString());
  document.cookie=c_name + "=" + c_value;
}
/**
 * Determine whether the animation cookie has been set
 * @return {boolean} false if cookie exists, true if cookie was set and animation should continue
 */
function checkCookie(){
var username=getCookie("played");
if (username!==null && username!=="")
  {
  // Do not play animation
  return false;
  }
else
  {
  // Play Animation
  setCookie("played","true",365);
  return true;
  }
}

Updated for JSLinting