javascript中的字符串中出现变量，该如何连接

举例：

var account = document.getElementById("change_account_<{$aff.Id}>").value;
var password = document.getElementById("change_password_<{$aff.Id}>").value;
var transactionCrawled = document.getElementById("change_transactionCrawled_<{$aff.Id}>").value;

$.ajax({
  type: "POST",
  url: "b_aff_aff_change.php",
  data: "account="+account+"&id=<{$aff.Id}>&password="+password+"&transactionCrawled="+transactionCrawled,

});

用+作连接符即可