Javascript Image Width

Hi guys,

I'm having a slight problem with the random image javascript codes. Is there any way to change the width and height of the image? Here is the code -

<HEAD>
<script LANGUAGE="JavaScript">

<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->

<!-- Begin
// Set up the image files to be used.
var theImages = new Array() // do not change this
// To add more image files, continue with the
// pattern below, adding to the array.

theImages[0] = 'img/1.png'
theImages[1] = 'img/2.png'
theImages[2] = 'img/3.png'
theImages[3] = 'img/4.png'
theImages[4] = 'img/5.png'
theImages[5] = 'img/6.png'

// do not edit anything below this line

var j = 0
var p = theImages.length;
var preBuffer = new Array()
for (i = 0; i < p; i++){
  preBuffer[i] = new Image()
  preBuffer[i].src = theImages[i]
}
var whichImage = Math.round(Math.random()*(p-1));
function showImage(){
document.write('<img src="'+theImages[whichImage]+'">');
}

//  End -->
</script>
<HEAD>
<BODY>
<script LANGUAGE="JavaScript">
<!-- Begin
showImage();
//  End -->
</script>