Bootstrap datepicker two way function

I have a bootstrap datepicker I wanted to create a date range in one object only and triggered by pressing shift key and when the user clicked ctrl key the function will shift to multi dates is that possible? Sorry I am just a newbie in Javascript. Any help would be very much appreciated. Thank you so much!


Here is what I have so far.

<div class="col-xs-12">
<input class="form-control" type="text" id="multi" name="multi" required>
<div class="help-block with-errors"></div>
</div>

<script>
$('#multi').datepicker({
multidate: true,
format: 'mm-dd-yyyy',
forceParse: false

}).on('hide', function (e) {
e.stopPropagation();
})
</script>

$("#multi").on('keydown', function (event) {
if (event.shiftKey === true) {
isShift = true;
//alert(isShift);
console.log(isShift);
// isCtrl = false;
} else if (event.ctrlKey === true) {
//alert('ey ctrl press');
isCtrl = true;
console.log(isCtrl);
//isShift = false;
} else {

return false
}
});