function togglePrevious(el) {
 var previous=el.previousSibling;
 while(previous.nodeType != 1) previous=previous.previousSibling;
 previous.style.display=((previous.style.display=="none") ? "block" : "none");
}

function getElementsByTagAndClassName(tag,cname) {
 var tags=document.getElementsByTagName(tag);
 var cEls=new Array();
 for (i=0; i<tags.length; i++) {
  var rE = new RegExp("(^|\s)" + cname + "(\s|$)");
   if (rE.test(tags[i].className)) {
   cEls.push(tags[i]);
   }
  }
 return cEls;
}
function togglePreviousByTagAndClassName(tag,cname) {
 var ccn="clicker";
 clickers=getElementsByTagAndClassName(tag,cname);
 for (i=0; i<clickers.length; i++) {
  clickers[i].className+=" "+ccn;
  clickers[i].onclick=function() {togglePrevious(this)}
  togglePrevious(clickers[i]);
 }
}
window.onload=function(){togglePreviousByTagAndClassName('div','overflow_text_trigger')}