function cartao(num){
cartao_atual="cartao_pgto" + num;
c_atual="cartao" + num;
document.getElementById('cartao_pgto1').style.display="none";
document.getElementById('cartao1').style.background="#FFFFFF";
document.getElementById('cartao_pgto2').style.display="none";
document.getElementById('cartao2').style.background="#FFFFFF";
document.getElementById('cartao_pgto3').style.display="none";
document.getElementById('cartao3').style.background="#FFFFFF";
document.getElementById('cartao_pgto4').style.display="none";
document.getElementById('cartao4').style.background="#FFFFFF";
//ativa o cartão
//document.getElementById('cartao_pgto4').style.display="block";
document.getElementById(cartao_atual).style.display="block";
document.getElementById(c_atual).style.background="#E8E4D9";
}