function getSelectionBoundaryElement(isStart) {
var range, sel, container;
if (document.selection) {
range = document.selection.createRange();
range.collapse(isStart);
return range.parentElement();
} else {
sel = window.getSelection();
if (sel.getRangeAt) {
if (sel.rangeCount > 0) {
range = sel.getRangeAt(0);
}
} else {
// Old WebKit
range = document.createRange();
range.setStart(sel.anchorNode, sel.anchorOffset);
range.setEnd(sel.focusNode, sel.focusOffset);
// Handle the case when the selection was selected backwards (from the end to the start in the document)
if (range.collapsed !== sel.isCollapsed) {
range.setStart(sel.focusNode, sel.focusOffset);
range.setEnd(sel.anchorNode, sel.anchorOffset);
}
}
if (range) {
container = range[isStart ? "startContainer" : "endContainer"];
// Check if the container is a text node and return its parent if so
return container.nodeType === 3 ? container.parentNode : container;
}
}
}