Cambiar imagen

Lo que me pides si que se puede hacer pero no con html sino con javascript.
Este codigo tienes que insertarlo en la cabecera.
Lo unico que debes modificar son las imagenes el resto respetalo a no ser que controles el tema del javascript.
<!--Two steps to installing this script-->
<!--1) Copy everything below, and paste in HEAD section of page-->
<script language="JavaScript1.1">
<!--
/*
JavaScript Image slideshow:
By Website Abstraction (www.wsabstract.com)
Over 200+ free JavaScript here!
*/
var slideimages=new Array()
var slidelinks=new Array()
function slideshowimages(){
for (i=0;i<slideshowimages.arguments.length;i++){
slideimages=new Image()
slideimages.src=slideshowimages.arguments
}
}
function slideshowlinks(){
for (i=0;i<slideshowlinks.arguments.length;i++)
slidelinks=slideshowlinks.arguments
}
function gotoshow(){
if (!window.winslide||winslide.closed)
winslide=window.open(slidelinks[whichlink])
else
winslide.location=slidelinks[whichlink]
winslide.focus()
}
//-->
</script>
<!--2) Copy below, and paste in BODY section of page-->
<!--To configure images, refer to comments below-->
<a href="javascript:gotoshow()"><img src="img1.gif" name="slide" border=0></a>
<script>
<!--
//configure the paths of the images, plus corresponding target links
slideshowimages("img1.gif","img2.gif","img3.gif")
slideshowlinks("http://wsabstract.com","http://dynamicdrive.com","http://java-scripts.net")
//configure the speed of the slideshow, in miliseconds
var slideshowspeed=2000
var whichlink=0
var whichimage=0
function slideit(){
if (!document.images)
return
document.images.slide.src=slideimages[whichimage].src
whichlink=whichimage
if (whichimage<slideimages.length-1)
whichimage++
else
whichimage=0
setTimeout("slideit()",slideshowspeed)
}
slideit()
//-->
</script>
<p align="center"><font face="arial" size="-2">This free script provided by</font><br>
<font face="arial, helvetica" size="-2"><a href="http://wsabstract.com">Website
Abstraction</a></font></p>