function foco (txt, amosar){
	if (document.getElementById(txt).value != amosar) {
		document.getElementById(txt).value = document.getElementById(txt).value;
	}
	else {
		document.getElementById(txt).value = '';
	}
}

function saida(txt, amosar){
	if (document.getElementById(txt).value == '') {
		document.getElementById(txt).value = amosar;
	}
}

function valida(){
	var err=0;
	
	if (document.getElementById("nome").value == "Nombre" || document.getElementById("nome").value == '' ){
		err++;
	}
	if (document.getElementById("correo").value == "Email" || document.getElementById("correo").value == '' ){
		err++;
	}
	if (document.getElementById("pais").value == "País" || document.getElementById("pais").value == '' ){
		err++;
	}
	if (document.getElementById("mensaxe").value == "Observaciones" || document.getElementById("mensaxe").value == '' ){
		err++;
	}

	if (err>0){
		document.getElementById("erro").innerHTML = "Debes cubrir todos los campos.";
		return false;
	}
	else{
		document.getElementById("erro").innerHTML = "";
	}

}

window.onload = function(){
	document.getElementById("nome").value = "Nombre";
	document.getElementById("correo").value = "Email";
	document.getElementById("pais").value = "País";
	document.getElementById("mensaxe").value = "Mensaje";
	document.getElementById("contacta").onsubmit=valida;
}