Note: Keep in mind one thing that TAB Key only fires on onkeydown and the onkeyup event. No onkeypress event is fired for TAB key.
Call the Function From Asp.net C#/VB.Net TextBox Event:
<asp:TextBox runat="server" ID="txt" onkeydown="DetectTab(event)"></asp:TextBox>
Note: 9 is the key code of TAB key.
Hope now you can take necessary action by detecting the TAB key.
Script tested for:
1. Internet Explorer
2. Mozilla Firefox
4. Google Chrome