/*
* createCookie(name,value,days)
* function create cookie with define name
*/
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;
}

/*
* readCookie(name)
* function read cookie with define name
* if exsist - return cookie value
* if not exsist - return null
*/
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;
}

/*
* eraseCookie(name)
* function erase cookie with define name
*/
function eraseCookie(name)
{
	createCookie(name,"",-1);
}

/*
 * validates an email address
 */
function isValidEmailAddress(address) {
	var exp = /\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*/;
	return exp.test(address);
}

/*
* Adds an event to body onload
*/
function addLoadEvent(func) {
  var oldonload = window.onload;
  if (typeof window.onload != 'function') {
    window.onload = func;
  } else {
    window.onload = function() {
      oldonload();
      func();
    }
  }
}

/*
* Adds an event to body onresize
*/
function addResizeEvent(func) 
{
    var oldonresize = window.onresize;
    if (typeof window.onresize != 'function') 
        window.onresize = func;
    else 
    {
        window.onresize = function() 
            {
                if (oldonresize) 
                    oldonresize();
                func();
            }
    }
}