The "Add Account Offer" request has been submitted successfully with the order number css_334560.

<div id="secondColumn" class="floatBreaker">
<div id="mainContents">
<h1>Add Account Offers                     </h1>
<div class="infoBox">
<div class="topLine">
<div class="txtLineRight">
<div class="txtLineLeft">
<div class="txt">
<span>The "Add Account Offer" request has been submitted successfully with the order number css_334560.</span>
</div>
</div>

String a = driver.findElement(By.xpath("//div[@class='txt']/span")).getText();
a = a.substring(a.lastIndexOf(' ') + 1).replace(".", "");

var snapElements = document.evaluate(
    './/text()[contains(.,"Add Account Offer")]',
    document.body, null, XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);

var txt = document.evaluate(
    './/text()[contains(.,"Add Account Offer")]',
    document.body, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null);

var txt = document.querySelector('.txt');
if (txt) { txt = txt.textContent; }

var txt = document.getElementsByClassName('txt');
if (txt[0]) { txt = txt[0].textContent; }

var css = txt.match(/css_d+/);