document.getElementById(" ").src not working?
<p>I want to be able to choose the Battery 9 inside the dropdownlist.<br>
I want the image of Battery 9 to show in the img tag.<br>
Am I doing something wrong?</p>

<pre><code>HEAD
function checkBatteryLife(){
if(document.getElementById('batterylifes').value == 'batterylife9'){
    document.getElementsByTagName('batteryID').src = 'battery9.png';
}
BODY
&lt;img alt="" src="" name="batteryID" onclick="checkBatteryLife()"&gt;
&lt;/br&gt;
&lt;select id="batterylifes" onchange="checkBatteryLife()"&gt;
&lt;option name="batteryIMG" value="batterylife9"&gt;Battery 9&lt;/option&gt;
&lt;/select&gt;
</code></pre>
