function set_cookie( name, value, days )
{
	var expires = '';
	if ( typeof( days ) == 'number' )
	{
		var d = new Date();
		d.setTime( d.getTime() + days * 24 * 60 * 60 * 1000 );
		expires = '; expires=' + d.toGMTString();
	}
	document.cookie = name + '=' + escape( value ) + expires + '; path=/';
}

function get_cookie( name)
{
	var re = new RegExp( '(\;|^)[^;]*(' + name + ')\=([^;]*)(;|$)' );
	var res = re.exec( document.cookie );
	return res != null ? unescape( res[ 3 ] ) : null;
}

function delete_cookie( name )
{
	set_cookie( name, '', -1 );
}