I am trying to make a validation rule to go along with my apporval process.  I need to lock the stagename pick list for 3 of my stages below. The code I have kinda works. I just can not save any opportutiny that is within that stage. 

My question is: how do I make the validation rule where as once the opportunity is in that stage (after apporval) the validation turns off for that stage so I can modify and save that opportunity.

AND(
$Profile.Name <> "System Administrator",
OR(
ISPICKVAL(StageName, "Pursue"),
ISPICKVAL(StageName, "Target"), 
ISPICKVAL(StageName, "Bid")
))

I am trying to make a validation rule to go along with my apporval process.  I need to lock the stagename pick list for 3 of my stages below. The code I have kinda works. I just can not save any opportutiny that is within that stage. 

My question is: how do I make the validation rule where as once the opportunity is in that stage (after apporval) the validation turns off for that stage so I can modify and save that opportunity.

AND(
$Profile.Name <> "System Administrator",
OR(
ISPICKVAL(StageName, "Pursue"),
ISPICKVAL(StageName, "Target"), 
ISPICKVAL(StageName, "Bid")
))