replaceHtml

JAVASCRIPT:

1.  
2. /* This is much faster than using (el.innerHTML = str) when there are many
3. existing descendants, because in some browsers, innerHTML spends much longer
4. removing existing elements than it does creating new ones. */
5. function replaceHtml(el, html) {
6.         var oldEl = (typeof el === "string" ? document.getElementById(el) : el);
7.         var newEl = document.createElement(oldEl.nodeName);
8.         // Preserve the element's id and class (other properties are lost)
9.         newEl.id = oldEl.id;
10.         newEl.className = oldEl.className;
11.         // Replace the old with the new
12.         newEl.innerHTML = html;
13.         oldEl.parentNode.replaceChild(newEl, oldEl);
14.         /* Since we just removed the old element from the DOM, return a reference
15.         to the new element, which can be used to restore variable references. */
16.         return newEl;
17. };
18.  

another way:

function replaceHtml(el, html) {
	var oldEl = (typeof el === "string" ? document.getElementById(el) : el);
	/*@cc_on // Pure innerHTML is slightly faster in IE
		oldEl.innerHTML = html;
		return oldEl;
	@*/
	var newEl = oldEl.cloneNode(false);
	newEl.innerHTML = html;
	oldEl.parentNode.replaceChild(newEl, oldEl);
	/* Since we just removed the old element from the DOM, return a reference
	to the new element, which can be used to restore variable references. */
	return newEl;
};