getSelection = function(input) {
		var result = {};
		if ('selectionStart' in input) {
			result.start = input.selectionStart;
			result.length = input.selectionEnd - result.start;
		} else if (document.selection) {
			input.focus();
			var sel = document.selection.createRange();
			var selLen = document.selection.createRange().text.length;
			sel.moveStart('character', -input.value.length);
			result.start = sel.text.length - selLen;
			result.length = selLen;
		}
		return result;
	}
Determines the current selection within a text input control.
Returns an object containing:
  - start
  - length

@param {object} input
@returns {object}