How to create a search that provides option for a LIKE and not LIKE option

[GaryZ]

Is there a way of creating a search where we can have both LIKE and NOT LIKE, based on user selected option?

ie. 

if $user_option_tk$ == True:

        | where NOT (error_string LIKE "%$filter_tk$%")

else:

        | where error_string LIKE "%$filter_tk$%"

[PickleRick]

Use the filter token to classify your data (set a synthetic field to either 1 or 0 (or true/false, green/red or whatever you want) and then do a "where" command depending on the option token - match eithee the 0s or 1s of your synthetic field.