First set Image Tag with a blank image like 1 x 1 pixel white image.
Then use Javscript
You'll need to use javascript for this:
<img src="white.jpg" id="RunTimemage" />
<script type="text/javascript">
document.getElementById("RunTimeImage").src = "image3.jpg";
</script>
Also you can toggle its visibility too if you want:
Declare it invisible.
<img src="" style="visibility:hidden"></img>
Make it visible:
document.getElementById(RunTimeImage).style.visibility = 'hidden';