关键字高亮显示，js轻松实现

<script>
    //关键字高亮显示func
    function InitialKeywordsShow(_keywords, obj, caseTrue) {
        //var reg = new RegExp(_keywords, "g");//区分大小写
        var reg = new RegExp(_keywords, "gi"); //不区分大小写
        if (caseTrue) {
            var reg = new RegExp(_keywords, "g");
        }
        if (obj && obj.childNodes && obj.childNodes.length > 0) {
            for (var i = 0; i < obj.childNodes.length; i++) {
                if (obj.childNodes[i].nodeType == 3 && obj.childNodes[i].nodeValue && obj.childNodes[i].nodeValue.length > 0) {
                    var txtnew = obj.childNodes[i].nodeValue.replace(reg, "<font color=‘red‘ style=‘ background:#e48b00;color:#fff;‘>" + _keywords + "</font>");
                    var _span = document.createElement("span");
                    _span.innerHTML = txtnew;
                    obj.replaceChild(_span, obj.childNodes[i]);
                }
                else if (obj.childNodes[i].nodeType == 1) {
                    InitialKeywordsShow(_keywords, obj.childNodes[i], caseTrue);
                }
            }
        }
    }
    //搜索func
    function SearchClick() {
        var fonts = document.getElementsByTagName("font");
        if (fonts && fonts.length > 0) {
            for (var i = 0; i < fonts.length; i++) {
                fonts[i].style.backgroundColor = "#fff";
                fonts[i].style.color = "black"
            }
        }
        var keyWords = document.getElementById("txtKeywords").value;
        var obj_content = document.getElementById("content");
        if (!keyWords) {
            alert("请输入关键字");
            return false;
        }
        var upTrue = document.getElementById("chkUp").checked;
        InitialKeywordsShow(keyWords, obj_content, upTrue);
    }
</script>