Usually the menu links to an URL. So..
In your web config file have like this
<system.web>
<authorization>
<deny users="?" />
</authorization>
</system.web>
<location path="Default2.aspx">
<system.web>
<authorization>
<allow users="Jack" />
<deny users="*" />
</authorization>
</system.web>
</location>
so the default2.aspx will be only allowed for the users assigned. Can use comma separated users.
For more detail refer this link..
http://www.asp.net/security/tutorials/user-based-authorization-cs[
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the Microsoft documentation
http://msdn.microsoft.com/en-us/library/wce3kxhd.aspx[
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