Checking Potion Effect Levels

[IViddyy]

Hi im trying to make talismans that give different haste levels when worn.But im trying to make it so if the player already have haste it adds the haste level to the talisman's haste level.This what i have for now (it only gives the haste)

variables:
    {currenthaste.%player%} = 0

Every 3 seconds:
     Loop all players:
          If loop-player is wearing chainmail chestplate named "End Stone Talisman":
               set {currenthaste.%loop-player%} to 1
          else If loop-player is wearing chainmail chestplate named "Purpur Talisman":
               set {currenthaste.%loop-player%} to 3
          else If loop-player is wearing chainmail chestplate named "Purple Concrete Talisman":
               set {currenthaste.%loop-player%} to 5
          else:
               set {currenthaste.%loop-player%} to 0
          if {currenthaste.%loop-player%} is 0:
               set {currenthaste.%loop-player%} to 0
          else:
               Apply haste {currenthaste.%loop-player%} without particles to loop-player for 3 seconds