插入范围内容

HTML

<section id="wrap">
    <article id="main">
        <h1>游子吟</h1>
        <h2>孟郊</h2>
        <p>慈母手中线，游子身上衣。临行密密缝，意恐迟迟归。谁言寸草心，报得三春晖。</p>
    </article>
    <header>
        <input type="button" value="创建范围" onclick="createrange()" />
    </header>
    <footer>
        <dl>
            <dt>范围1</dt>
            <dd>Start Container(开始点的父节点）:<span id="txtStartContainer1"></span></dd>
            <dd>Start Offset(开始点的偏移值）:<span id="txtStartOffset1"></span></dd>
            <dd>End Container(结束点的父节点）:<span id="txtEndContainer1"></span></dd>
            <dd>End Offset(结束点的偏移值）:<span id="txtEndOffset1"></span></dd>
            <dd>Common Ancestor（共同祖先节点）:<span id="txtCommonAncestor1"></span></dd>
        </dl>
        <dl>
            <dt>范围2</dt>
            <dd>Start Container(开始点的父节点）:<span id="txtStartContainer2"></span></dd>
            <dd>Start Offset(开始点的偏移值）:<span id="txtStartOffset2"></span></dd>
            <dd>End Container(结束点的父节点）:<span id="txtEndContainer2"></span></dd>
            <dd>End Offset(结束点的偏移值）:<span id="txtEndOffset2"></span></dd>
            <dd>Common Ancestor（共同祖先节点）:<span id="txtCommonAncestor2"></span></dd>
        </dl>
    </footer>
</section>
    					    

JS

//插入范围内容
function createrange() {
    var range1 = document.createRange();
    var main= document.getElementById("main");
    range1.setStart(main, 1);
    range1.setEnd(main, 4);
    var h1 = document.createElement("h1");
    h1.style.color = "red";
    h1.innerHTML =  "唐诗诵读";
    range1.insertNode(h1);
}
//高亮显示范围内容
function createrange() {
    var range1 = document.createRange();
    var p= document.getElementsByTagName("p")[0];
	var text = p.firstChild;
    range1.setStart(text, 24);
    range1.setEnd(text, 36);
	var span = document.createElement("span");
	span.style.color = "red";
	span.style.fontWeight = "bold";
    range1.surroundContents(span);
}