How to get innerHTML from parent DIV and the innerHTML stop at selected word?
like example, I will get the result alert innerHTML of This select some <b>is a <i>some, if I selected the 'asx' word.
Thank you
function selected(element) {
    var start = '';
    var end = '';
    var doc = element.ownerDocument || element.document;
    var win = doc.defaultView || doc.parentWindow;
    var sel;
    if (typeof win.getSelection != "undefined") {
        sel = win.getSelection();
        if (sel.rangeCount > 0) {
            var range = win.getSelection().getRangeAt(0);
            
            var preCaretRange = range.cloneRange();
            preCaretRange.selectNodeContents(element);
            preCaretRange.setEnd(range.startContainer, range.startOffset);
            var start = preCaretRange.toString();
            alert(start);
        }
    } 
}<div id="editor" contenteditable="true">This select some <b>is a <i>some asx</i> sdc</b> select some text in some here.</div>
<button type="button" onclick="selected(document.querySelector('#editor'))">edit</button> 
    