Single Mouseover:

Code:

Place in the <HEAD>:

<script language="JavaScript">
<!--
icona = new Image()   
icona.src = "/images/icon1a.gif"

iconb = new Image()
iconb.src = "/images/icon1.gif"

iconc = new Image()   
iconc.src = "/images/icon2a.gif"

icond = new Image()
icond.src = "/images/icon2.gif"

icone = new Image()   
icone.src = "/images/icon3a.gif"

iconf = new Image()
iconf.src = "/images/icon3.gif"

icong = new Image()   
icong.src = "/images/icon4a.gif"

iconh = new Image()
iconh.src = "/images/icon4.gif"

iconi = new Image()   
iconi.src = "/images/icon5a.gif"

iconj = new Image()
iconj.src = "/images/icon5.gif"

iconk = new Image()   
iconk.src = "/images/icon6a.gif"

iconl = new Image()
iconl.src = "/images/icon6.gif"

iconm = new Image()   
iconm.src = "/images/icon7a.gif"

iconn = new Image()
iconn.src = "/images/icon7.gif"

icono = new Image()   
icono.src = "/images/icon8a.gif"

iconp = new Image()
iconp.src = "/images/icon8.gif"

iconq = new Image()   
iconq.src = "/images/icon9a.gif"

iconr = new Image()
iconr.src = "/images/icon9.gif"

icons = new Image()   
icons.src = "/images/icon10a.gif"

icont = new Image()
icont.src = "/images/icon10.gif"

iconu = new Image()   
iconu.src = "/images/icon11a.gif"

iconv = new Image()
iconv.src = "/images/icon11.gif"

iconw = new Image()   
iconw.src = "/images/icon12a.gif"

iconx = new Image()
iconx.src = "/images/icon12.gif"

icony = new Image()   
icony.src = "/images/icon13a.gif"

iconz = new Image()
iconz.src = "/images/icon13.gif"

iconaa = new Image()   
iconaa.src = "/images/icon14a.gif"

iconbb = new Image()
iconbb.src = "/images/icon14.gif"

iconcc = new Image()   
iconcc.src = "/images/icon15a.gif"

icondd = new Image()
icondd.src = "/images/icon15.gif"

iconee = new Image()   
iconee.src = "/images/icon16a.gif"

iconff = new Image()
iconff.src = "/images/icon16.gif"

icongg = new Image()   
icongg.src = "/images/icon17a.gif"

iconhh = new Image()
iconhh.src = "/images/icon17.gif"

iconii = new Image()   
iconii.src = "/images/icon18a.gif"

iconjj = new Image()
iconjj.src = "/images/icon18.gif"

iconkk = new Image()   
iconkk.src = "/images/icon19a.gif"

iconll = new Image()
iconll.src = "/images/icon19.gif"

iconmm = new Image()   
iconmm.src = "/images/icon20a.gif"

iconnn = new Image()
iconnn.src = "/images/icon20.gif"

function imageChange(imgName,imgSrc){
document.images[imgName].src = eval(imgSrc +".src")
}
//-->
</script>

Place in the <BODY>:

<a href onMouseOver="imageChange('image1','icona')" onMouseOut="imageChange('image1','iconb')"><img src="/images/icon1.gif" border="0" name="image1"></a><br>
<a href onMouseOver="imageChange('image2','iconc')" onMouseOut="imageChange('image2','icond')"><img src="/images/icon2.gif" border="0" name="image2"></a><br>
<a href onMouseOver="imageChange('image3','icone')" onMouseOut="imageChange('image3','iconf')"><img src="/images/icon3.gif" border="0" name="image3"></a><br>
<a href onMouseOver="imageChange('image4','icong')" onMouseOut="imageChange('image4','iconh')"><img src="/images/icon4.gif" border="0" name="image4"></a><br>
<a href onMouseOver="imageChange('image5','iconi')" onMouseOut="imageChange('image5','iconj')"><img src="/images/icon5.gif" border="0" name="image5"></a><br>
<a href onMouseOver="imageChange('image6','iconk')" onMouseOut="imageChange('image6','iconl')"><img src="/images/icon6.gif" border="0" name="image6"></a><br>
<a href onMouseOver="imageChange('image7','iconm')" onMouseOut="imageChange('image7','iconn')"><img src="/images/icon7.gif" border="0" name="image7"></a><br>
<a href onMouseOver="imageChange('image8','icono')" onMouseOut="imageChange('image8','iconp')"><img src="/images/icon8.gif" border="0" name="image8"></a><br>
<a href onMouseOver="imageChange('image9','iconq')" onMouseOut="imageChange('image9','iconr')"><img src="/images/icon9.gif" border="0" name="image9"></a><br>
<a href onMouseOver="imageChange('image10','icons')" onMouseOut="imageChange('image10','icont')"><img src="/images/icon10.gif" border="0" name="image10"></a><br>
<a href onMouseOver="imageChange('image11','iconu')" onMouseOut="imageChange('image11','iconv')"><img src="/images/icon11.gif" border="0" name="image11"></a><br>
<a href onMouseOver="imageChange('image12','iconw')" onMouseOut="imageChange('image12','iconx')"><img src="/images/icon12.gif" border="0" name="image12"></a><br>
<a href onMouseOver="imageChange('image13','icony')" onMouseOut="imageChange('image13','iconz')"><img src="/images/icon13.gif" border="0" name="image13"></a><br>
<a href onMouseOver="imageChange('image14','iconaa')" onMouseOut="imageChange('image14','iconbb')"><img src="/images/icon14.gif" border="0" name="image14"></a><br>
<a href onMouseOver="imageChange('image15','iconcc')" onMouseOut="imageChange('image15','icondd')"><img src="/images/icon15.gif" border="0" name="image15"></a><br>
<a href onMouseOver="imageChange('image16','iconee')" onMouseOut="imageChange('image16','iconff')"><img src="/images/icon16.gif" border="0" name="image16"></a><br>
<a href onMouseOver="imageChange('image17','icongg')" onMouseOut="imageChange('image17','iconhh')"><img src="/images/icon17.gif" border="0" name="image17"></a><br>
<a href onMouseOver="imageChange('image18','iconii')" onMouseOut="imageChange('image18','iconjj')"><img src="/images/icon18.gif" border="0" name="image18"></a><br>
<a href onMouseOver="imageChange('image19','iconkk')" onMouseOut="imageChange('image19','iconll')"><img src="/images/icon19.gif" border="0" name="image19"></a><br>
<a href onMouseOver="imageChange('image20','iconmm')" onMouseOut="imageChange('image20','iconnn')"><img src="/images/icon20.gif" border="0" name="image20"></a><br>