function toggleNext(el) {
 var next=el.nextSibling;
 while(next.nodeType != 1) next=next.nextSibling;
 next.style.display=((next.style.display=="none") ? "block" : "none");
}

function toggleNextByTagName(tname) {
 var ccn="clicker";
 var clickers=document.getElementsByTagName(tname);
 for (i=0; i<clickers.length; i++) {
 clickers[i].className+=" "+ccn;
 clickers[i].onclick=function() {toggleNext(this)}
 toggleNext(clickers[i]);
 }
}
			
window.onload=function() {toggleNextByTagName('h4')}