1$(document)
2    .one('focus.textarea', '.autoExpand', function(){
3        var savedValue = this.value;
4        this.value = '';
5        this.baseScrollHeight = this.scrollHeight;
6        this.value = savedValue;
7    })
8    .on('input.textarea', '.autoExpand', function(){
9        var minRows = this.getAttribute('data-min-rows')|0,
10            rows;
11        this.rows = minRows;
12        rows = Math.ceil((this.scrollHeight - this.baseScrollHeight) / 16);
13        this.rows = minRows + rows;
14    });
15