function contrae(id_txt){
	if (document.getElementById)
	{
		var i=id_txt;          
		
		document.getElementById("txt"+i).style.display="none";
		document.getElementById("c"+i).value=''; 
	}
}

function expande(id_txt){
	if (document.getElementById)
	{
		var i=id_txt;        
		
		document.getElementById("txt"+i).style.display="block";
		document.getElementById("c"+i).value='on'; 
	}
}

function ver_txt(id_txt){
	var i=id_txt;
	if (document.getElementById("c"+i).value=='on')
		contrae(i);
	else
		expande(i);
	
}