String.prototype.trim = function() {
  return this.replace(/^\s+|\s+$/g,"");
}

function createCookie(name,value,days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime()+(days*24*60*60*1000));
    var expires = "; expires="+date.toGMTString();
  } else {
    var expires = "";
  }
  document.cookie = name+"="+value+expires+"; path=/";
}

function readCookie(name) {
  var nameEQ = name + "=";
  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,c.length);
    }
    if (c.indexOf(nameEQ) == 0) {
      return c.substring(nameEQ.length,c.length);
    }
  }
  return null;
}

function eraseCookie(name) {
  createCookie(name,"",-1);
}

function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      if (oldonload) {
        oldonload();
      }
      func();
    }
  }
}