<script type="text/javascript">     
divWeHave = document.getElementsByTagName('DIV');     
replacement = new Array (     
'Первая замена',     
'вторая',     
'третья и т.д.'     
);     

numer = 0;     

for(i=0;i<divWeHave.length;i++){     
if(divWeHave[i].className == 'forumModer'){     
divWeHave[i].innerHTML = replacement[numer]+divWeHave[i].innerHTML.slice(16);     
numer++;     
}     
}     
</script>