<script type="text/javascript" language="javascript">   
e=document.getElementsByTagName("TD");   
for(k=15; k<e.length;k++) {   
if(e[k].className=='posttdMessage') {   
s=e[k].innerHTML;   
while (s.indexOf('[blink]') != -1){   
s=s.replace('[blink]','<blink>'); s=s.replace('[/blink]','</blink>');   
e[k].innerHTML=s;   
}   
} }   
</script>

<input type="button" accesskey="y" value="blink" onclick="simpletag('blink','','','message',''); return false;" class="codeButtons" title="Вставить мерцающий текст" name="blink" />