/*
Exemplo de utilizacao
  <input name="cpf" type="text" id="cnpj" size="18" maxlength="18" onKeyPress="return formataCPF(this,event);">
*/
function formataCPF(fld, e) {
//var sep = 0;
var key = '';
var i = j = 0;
var len = len2 = 0;
var strCheck = '0123456789';
var aux = aux2 = '';
var whichCode = (window.Event) ? e.which : e.keyCode;
if (whichCode == 13) return true;  // Enter
key = String.fromCharCode(whichCode);  // Get key value from key code
if (strCheck.indexOf(key) == -1) return false;  // Not a valid key
len = fld.value.length;

if((len+1) > fld.maxLength || (len+1) > 14)
	return false;

switch(len)
{
	case 3:
	case 7:
		fld.value = fld.value+'.';
		break;
	case 11:
		fld.value = fld.value + '-';
		break;
	default:
		break;
}

return true;
}