<script type="text/javascript">
// simple image viewer: her.bird@gmail.com

// INSERT YOUR IMAGE URLS HERE

imgList = new Array(
"img1.gif","img2.jpg","img3.bmp"
);

// THE MAIN FUNCTION, NEEDS NO CHANGES

function changeImage(){
imgFetch = document.canvasForm.canvasSelect.value;
if(imgFetch == ""){
false;
}else{
document.write("<div><img border='0' src='"+imgFetch+"' /></div>");
document.write("go back");
}
}

// THIS IS THE SELECT FORM

document.write("<form name='canvasForm'>");
document.write("<select name='canvasSelect' size='1' onchange='changeImage()'>");
document.write("<option value=''>select image...</option>");
for(imgC=0;imgC<imgList.length;imgC++){
document.write("<option value='"+imgList[imgC]+"'>"+imgList[imgC]+"</option>");
}
document.write("</select>");
document.write("</form>");
document.write("<div id='theCanvas'></div>");
</script>

1) First you have an array that keeps all of your image URLs.

2) Then the function that loads up the value from the select box.

3) And writes the <img> tag with the loaded image value (URL).