a/21478968/1636522

by wared

HTML

<div id="availability" class="a-section a-spacing-none">   
    <span class="a-size-medium a-color-success">       
            Only 14 left in stock.        
    </span>
</div>

JavaScript

try {
    alert(document.getElementById('availability').firstChild().innerHTML());
} catch(e) {
    alert(e.message);
}