Why does it work once and then move to the same spot?

So i want to move the player every time he clicks F but instead this works once and then just moves the player to one place. This is a localscript inside StarterCharacterScripts

UIS.InputBegan:connect(function(Input)
    local MouseInput = Input.UserInputType 
    local KeyCode = Input.KeyCode

    if KeyCode == Enum.KeyCode.F then
      plr.Character.HumanoidRootPart.CFrame =                    
      CFrame.new(plr.Character.Head.CFrame.lookVector * 15)
    end
end)