function classExists(c) {
    return ((typeof(c) == "function" && typeof(c.prototype) == "object") ? true : false);
}

function setCookie(c_name,value,expiredays)
{
	var exdate=new Date();
	exdate.setDate(exdate.getDate()+expiredays);
	document.cookie=c_name+ "=" +escape(value)+
	((expiredays==null) ? "" : ";expires="+exdate.toGMTString());
}

function getCookie(c_name)
{
	if (document.cookie.length>0)
	  {
	  c_start=document.cookie.indexOf(c_name + "=");
	  if (c_start!=-1)
	    {
	    c_start=c_start + c_name.length+1;
	    c_end=document.cookie.indexOf(";",c_start);
	    if (c_end==-1) c_end=document.cookie.length;
	    return unescape(document.cookie.substring(c_start,c_end));
	    }
	  }
	return "";
}

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();
    }
  }
}

function addUnLoadEvent(func) {
  var oldonunload = window.onunload;
  if (typeof window.onunload != 'function') {
    window.onunload = func;
  } else {
    window.onunload = function() {
      if (oldonunload) {
        oldonunload();
      }
      func();
    }
  }
}