I got code below off the internet, and it offers much of what I want, but rather than automatically cycling through the images, I want the user to press a next button to see the next image. I don't know javascript *at all*, but I'm hoping someone here knows it well enough to show me how it's done? 
Code:
<script type="text/javascript">
// Flexible Image Slideshow- By JavaScriptKit.com ([URL unfurl="true"]http://www.javascriptkit.com)[/URL]
// For this and over 400+ free scripts, visit JavaScript Kit- [URL unfurl="true"]http://www.javascriptkit.com/[/URL]
// This notice must stay intact for use
var ultimateshow=new Array()
//ultimateshow[x]=["path to image", "OPTIONAL link for image", "OPTIONAL link target"]
ultimateshow[0]=['dinosour.gif', '', '']
ultimateshow[1]=['crow.gif', '[URL unfurl="true"]http://www.dynamicdrive.com',[/URL] '_new']
ultimateshow[2]=['pig.gif', '[URL unfurl="true"]http://www.codingforums.com',[/URL] '']
//configure the below 3 variables to set the dimension/background color of the slideshow
var slidewidth="300px" //set to width of LARGEST image in your slideshow
var slideheight="261px" //set to height of LARGEST iamge in your slideshow
var slidecycles="3" //number of cycles before slideshow stops (ie: "2" or "continous")
var randomorder="no" //randomize the order in which images are displayed? "yes" or "no"
var preloadimages="yes" //preload images? "yes" or "no"
var slidebgcolor='white'
//configure the below variable to determine the delay between image rotations (in miliseconds)
var slidedelay=3000
////Do not edit pass this line////////////////
var ie=document.all
var dom=document.getElementById
var curcycle=0
if (preloadimages=="yes"){
for (i=0;i<ultimateshow.length;i++){
var cacheimage=new Image()
cacheimage.src=ultimateshow[i][0]
}
}
var currentslide=0
function randomize(targetarray){
ultimateshowCopy=new Array()
var the_one
var z=0
while (z<targetarray.length){
the_one=Math.floor(Math.random()*targetarray.length)
if (targetarray[the_one]!="_selected!"){
ultimateshowCopy[z]=targetarray[the_one]
targetarray[the_one]="_selected!"
z++
}
}
}
if (randomorder=="yes")
randomize(ultimateshow)
else
ultimateshowCopy=ultimateshow
function rotateimages(){
curcycle=(currentslide==0)? curcycle+1 : curcycle
ultcontainer='<center>'
if (ultimateshowCopy[currentslide][1]!="")
ultcontainer+='<a href="'+ultimateshowCopy[currentslide][1]+'" target="'+ultimateshowCopy[currentslide][2]+'">'
ultcontainer+='<img src="'+ultimateshowCopy[currentslide][0]+'" border="0">'
if (ultimateshowCopy[currentslide][1]!="")
ultcontainer+='</a>'
ultcontainer+='</center>'
if (ie||dom)
crossrotateobj.innerHTML=ultcontainer
if (currentslide==ultimateshow.length-1) currentslide=0
else currentslide++
if (curcycle==parseInt(slidecycles) && currentslide==0)
return
setTimeout("rotateimages()",slidedelay)
}
if (ie||dom)
document.write('<div id="slidedom" style="width:'+slidewidth+';height:'+slideheight+'; background-color:'+slidebgcolor+'"></div>')
function start_slider(){
crossrotateobj=dom? document.getElementById("slidedom") : document.all.slidedom
rotateimages()
}
if (ie||dom)
window.onload=start_slider
</script>