<textarea id="tValue" style="overflow-y:hidden; height:20px;" onpropertychange="this.style.height=this.scrollHeight + ‘px‘" oninput="this.style.height=this.scrollHeight + ‘px‘"></textarea>
textarea自动增高并隐藏滚动条
原文：http://www.cnblogs.com/sprine/p/4849733.html
