Internet Explorer显示e.which为undefined

Question

In Internet Explorer 8,在FireFox中event.which显示undefined并正常工作IE 9.我正在使用Textbox'onkeypress'活动

标记

<asp:TextBox runat="server" ID="tb1" MaxLength="3"
                        onkeypress="return MainCheckStrings(event);" />

它在FF,Chrome,Safari和Internet Explorer - 9中运行良好

任何的想法？

Answer 1

var charCode = evt.which || evt.keyCode;