set/overide session values via iRule

Same variable assign as Seth, but with a switch instead of multiple if:

session.custom.logontype =
set username [string trim [mcget {session.logon.last.logonname}]];
switch -glob $username { 
    "*@*" { return 1 } 
    "*\\\\*" { return 2 } 
    default { return 3 } 
}

I use session.logon.last.logonname and not session.logon.last.username to be sure logon page "Split domain from full Username" option does not change behavior.