How can i check if player does not exist using my existing code?

Help and Feedback Scripting Support
#1

I want my system to post an error message if the user inputted into the textbox is invalid. How would I go about doing this using my existing code?

local IO = game:GetService("ReplicatedStorage"):WaitForChild("Events").InvokeOrder

script.Parent.Start.MouseButton1Click:Connect(function() -- Enter button next to text box.
	local name = script.Parent.CustomerName.Text -- Text box user inputs text into.
	for _,v in pairs(game.Players:GetPlayers()) do
		if v.Name == name then
			IO:Fire(name)
		end
	end
	
end)
#2

You can do:

if not game.Players:FindFirstChild(name) then
    -- The code is invalid
end

Write that code right after you declare your name variable, BEFORE the for-loop.

Hope this helps!

#3 
local IO = game:GetService("ReplicatedStorage"):WaitForChild("Events"):WaitForChild("InvokeOrder")
local players = game:GetService("Players")
local localPlr = players.LocalPlayer
local localName = localPlr.Name
local start = script.Parent:WaitForChild("Start")
local customerName = script.Parent:WaitForChild("CustomerName")

start.MouseButton1Click:Connect(function()
	local plrName = customerName.Text
	if plrName == localName then
		return --dont want to allow players to invoke an order to themselves
	else
		if players:FindFirstChild(plrName) then
			IO:Fire(plrName)
		end
	end
end)