ll if it has not been set.
</div>







<dl class="details">

    

    

    

    

    

    

    

    

    

    

    

    

    

    

    

    
</dl>






        
            
<h4 class="name" id="onreadystatechange"><span class="type-signature"></span>onreadystatechange<span class="type-signature"></span></h4>




<div class="description">
    Sets the callback for the "readystatechange" event. This event callback is called with no parameters but the "this"
object is the XMLHttpRequest obje