How to press "Enter" to call a function?

I want to use "Enter" to call the "show()" of the "Button1" , how to ? Thank you very much!

<FCKeditorV2:FCKeditor ID="chatbuffer" runat="server" ></FCKeditorV2:FCKeditor>

<input id="Button1" type="button" value="button" onclick="show()" />