function setCookie( name, value, expiredays )
{
	var todayDate = new Date();
	todayDate.setDate( todayDate.getDate() + expiredays );
	document.cookie = name + "=" + escape( value ) + "; path=/; expires=" + todayDate.toGMTString() + ";"
}
function delete_cookie ( cookie_name ){
	var cookie_date = new Date ( );
	cookie_date.setTime ( cookie_date.getTime() - 1 );
	document.cookie = cookie_name += "=; expires=" + cookie_date.toGMTString();
}
function get_cookie( cookie_name ){
	var results = document.cookie.match ( '(^|;) ?' + cookie_name + '=([^;]*)(;|$)' );
	if ( results )   return ( unescape ( results[2] ) );
	else    return null;
}