How can I determine the background image url of a div via javascript?
<p>I've found plenty of information on how to change the background image of a div using Javascript, but I am trying to use Javacript to determine which background image is being displayed.  The code to set the image goes like this: </p>

<pre><code>document.getElementById("widgetField").style.background="url(includes/images/datepicker_open.png)";
</code></pre>

<p>I have tried every combination I can think of to access the background image url, but so far no dice: </p>

<pre><code>alert(document.getElementById("widgetField").style.backgroundImage.url);  - returns Undefined
alert(document.getElementById("widgetField").style.backgroundImage);  - empty response
alert(document.getElementById("widgetField").style.background);
alert(document.getElementById("widgetField").style.background.image);
alert(document.getElementById("widgetField").style.background.url);
alert(document.getElementById("widgetField").style.background.image.url);
alert(document.getElementById("widgetField").style.background.value);
alert(document.getElementById("widgetField").style.background.image.value);
alert(document.getElementById("widgetField").style.background.image.value);
alert(document.getElementById("widgetField").style.backgroundImage.value);
</code></pre>

<p>Does anyone know how to do this?  Is it possible?  </p>

<p>BTW, here is the way the image is being set in CSS in the beginning: </p>

<pre><code>#widgetField {
    width: 290px;
    height: 26px;
    background: url(../images/datepicker_closed.png);
    overflow: hidden;
    position: relative;
}
</code></pre>

<p><strong>UPDATE:</strong></p>

<p>If I run the following, it works: </p>

<pre><code>document.getElementById("widgetField").style.background="url(includes/images/datepicker_open.png)";
alert(document.getElementById("widgetField").style.background);
</code></pre>

<p>However, I cannot seem to access the URL property until it has been set by Javascript, even though it is already defined in the CSS file.  Is there a reason why the raw CSS setting is not accessible?  </p>
