js 选中文字，让鼠标选中文字

aaaaaaaaaaaaaaaaaaa
<div id="divID">
    xxxxxxxxxxxxxx<br />
    xxxxxxxxxxxxxx<br />
    xxxxxxxxxxxxxx<br />
    xxxxxxxxxxxxxx<br />
</div>
aaaaaaaaaaaaaaaaa

<script type="text/javascript">
function selectText(element) {
    var text = document.getElementById(element);
    if (document.body.createTextRange) {
        var range = document.body.createTextRange();
        range.moveToElementText(text);
        range.select();
    } else if (window.getSelection) {
        var selection = window.getSelection();
        var range = document.createRange();
        range.selectNodeContents(text);
        selection.removeAllRanges();
        selection.addRange(range);
        /*if(selection.setBaseAndExtent){
            selection.setBaseAndExtent(text, 0, text, 1);
        }*/
    } else {
        alert("none");
    }
};

//调用
selectText("divID");
</script>