Err.Raise or Throw New Exception - NOT STOPPING code

HI,

 Code in class module, vb.net

 I have code like this in a sub call TEST say

 If strPeriod.length < 1 then 
    msgbox("TEST1")
    err.raise(-99,"codezone","Period String fails"
end if

 If strPeriod.length < 1 then 
   msgbox("TEST2")
    throw new exception ("Period String fails")
end if

 When the error is forced both times the msgbox pops up in asp.net 2.0 ms vs 2005 applicatio, yet the code continues to run onto the next sub/function, I thought code would stop and show me a stand error asp.net page, but it does not.

 Even when I place a try, catch around the sub, the code still does not stop running...

 What am I missing ??
...