var mailcount = 0;
var namecount = 16; 
function cerrar(obj){ 
email=document.getElementById("emailNode"); 
email.parentNode.removeChild(email.parentNode.childNodes[mailcount+4]); 
mailcount --; 
namecount=namecount-3;
if (mailcount==0){ 
	document.getElementById("mailManagment" ).removeChild(document.getElementById("cerrarMail" )); 
} 
} 

function newEntry(inputName,text){ 
newInput = document.createElement("input" ); 
newInput.name="c"+namecount;
newInput.id="c"+namecount;
newInput.type="text"; 
newInput.size="8";
namecount++;
newInput1 = document.createElement("input" ); 
newInput1.name="c"+namecount;
newInput1.id="c"+namecount;
newInput1.type="text"; 
newInput1.size="8";
namecount++;
newInput2 = document.createElement("input" ); 
newInput2.name="c"+namecount;
newInput2.id="c"+namecount;
newInput2.type="text"; 
newInput2.size="8";
namecount++;
newNode = document.createElement("tr" ); 
newNode.appendChild(document.createElement("td" )); 
//newNode.appendChild(document.createElement("td" )); 
//newNode.firstChild.appendChild(document.createTextNode(text));
newNode.firstChild.appendChild(newInput);
newNode.firstChild.appendChild(document.createTextNode(" "));
newNode.firstChild.appendChild(newInput1); 
newNode.firstChild.appendChild(document.createTextNode(" "));
newNode.firstChild.appendChild(newInput2); 
return newNode; 
} 
function newMail(){ 
mailcount ++; 
num=mailcount+5;
email=document.getElementById("emailNode" ); 
//Creo el nuevo campo 
newNode=newEntry("email"+mailcount,"Dato "+num+": " ); 
//Muestro el nuevo campo 
email.parentNode.insertBefore(newNode,email); 

//Agregar el código para borrar el śltimo mail 
if (mailcount==1){ 
newClose1 = document.createElement("br" );
newClose = document.createElement("a" ); 
newClose.id="cerrarMail"; 
newClose.href="javascript:cerrar(this)";
newClose.appendChild(newClose1);
newClose.appendChild(document.createTextNode("Borrar śltimo" )); 
document.getElementById("mailManagment" ).appendChild(newClose); 
} 
} 

function calcularestadisticas(){
	vector=new Array();
	for (i=1;i<namecount;i++)
	{
		obj="c"+i;
		valor=document.getElementById(obj).value;
		numero=parseFloat(valor);
		if (!isNaN(numero))
		{
			vector.push(numero);
		}
	}
	vector.sort();
	if (vector.length>0) 
		mid1=Math.floor((vector.length-1)/2);
	if (vector.length>0) 
		mid2=Math.ceil((vector.length-1)/2);
	mediana=(vector[mid1]+vector[mid2])/2;
	suma=0;
	varianza=0;
	for (i=0;i<vector.length;i++)
	{
		suma+=vector[i];
		varianza=varianza+(vector[i]*vector[i]);
	}
	varianza=(varianza-suma*suma/vector.length)/(vector.length-1);
	desviacion=Math.sqrt(varianza);
	document.estad.datos.value=vector.length;
	document.estad.promedio.value=suma/vector.length;
	document.estad.varianza.value=varianza;
	document.estad.desviacion.value=desviacion;
	document.estad.mediana.value=mediana;
	
}