Try This:
<asp:textbox id="TextBox1" runat="server" onkeydown="KeysShortcut();"></asp:textbox>
<asp:textbox id="TextBox2" runat="server"></asp:textbox>
function KeysShortcut() {
if (event.keyCode == 190) {
document.getElementById('<%= TextBox2.ClientID %>').focus();
}
}