function sound()
{
	var m_frm = parent.frames[0];
	
	if (m_frm) {
		document.write("- <a id=aSound href='javascript:m_sound.playStop()'>musica " +
			((m_frm.location.href.indexOf("sound.htm") != -1) ? "off" : "on") + 
			"</a>"
		);
	}
	else
		return;
	
	this.playStop = function playStop()
	{
		var a = document.getElementById("aSound");
		if (a.innerHTML.indexOf("off") != -1) {
			m_frm.location.href = "mute.htm";
			a.innerHTML = "musica on";
		}
		else {
			m_frm.location.href = "sound.htm";
			a.innerHTML = "musica off";
		}
	}
}

var m_sound = new sound();