nodes html changer

replace_text.js

window.replaceTextIndex = [];
function replaceText(element, text, newText) {
    var regextPattern = new RegExp(text, "g");
    if (typeof element === 'string' || element instanceof String)
    	element = document.querySelector(element);
    element.childNodes.forEach(function(node, index) {
        if (node.tagName == "P" || node.tagName == "DIV" || node.tagName == undefined || node.tagName == "SPAN") {
            if (node.tagName == undefined && node.nodeValue != "") { // it's text		
				if(node.nodeType != Node.COMMENT_NODE && node.nodeValue.trim().length > 0)
                {
                	var newNodeElement = document.createElement("span");
                    newNodeElement.innerHTML = node.nodeValue.replace(regextPattern, function(match,i){
	                     if(window.replaceTextIndex[text] === undefined)
	                     	window.replaceTextIndex[text] = 0;
                        
	                     if(window.replaceTextIndex[text] > 2)
	                     	return text;
	                    
                        window.replaceTextIndex[text]++;
                         return newText;
                    });
	                node.parentNode.replaceChild(newNodeElement,node);
                }
            } else {
	            replaceText(element.childNodes[index],text,newText);
            }
        }
    })
}

// example
// <div id="content">Hi gist , <p style="color:red">this is test for gist</p> <div><p><span>bye gist</span></p></div>
// in script.js
// replaceText('#content','gist','Ahmed Ashraf')
// result
// <div id="content"><p>Hi Ahmed Ashraf , </p><p style="color:red">this is test for Ahmed Ashraf</p><p> </p><div><p><span>bye Ahmed Ashraf</span></p></div><p></p></div>