What function would I use to access a value from another player?

I have a button that allows you to challenge a player that you want to play against. Everything works fine, but I want to add a function where if the player you want to battle already has a request from someone else, the RequestRemote wont fire and give the player an error message. I just don't know what function can accomplish this because the Boolean value has to be accessed from the localscript.

The boolean "hasRequest" is created in everyone's Player. This is the value I want to check before sending a request.

Here is my LocalScript for reference:

local id = script.Parent.Parent:WaitForChild("PlayerID")
local text = script.Parent:WaitForChild("Battletext")
local Request = game.ReplicatedStorage.DefaultRequest
local localgui = game:GetService('Players').LocalPlayer:WaitForChild("PlayerGui")
local localplayerid = game.Players.LocalPlayer.UserId
local lookfor = game.ReplicatedStorage.BattleEvent
local lookForGameNextClick = true
local player = game:GetService("Players"):GetPlayerByUserId(id.Value)
local localname = game.Players.LocalPlayer.Name
local iswaiting = game:GetService('Players').LocalPlayer:WaitForChild("WaitingForPlayer")
local hasgui = game:GetService('Players').LocalPlayer:WaitForChild("hasRequest")



script.Parent.MouseButton1Click:connect(function()
    --print(id.Value)
    --print(localplayerid)

    if id.Value == localplayerid then -- can't battle yourself in the list
        script.Disabled = true
        text.Text = "Can't Do That"
        wait(2)
        script.Disabled = false
        text.Text = "BATTLE"

    else
        if hasgui.Value == true then
            print("True")
            text.Text = "Waiting!" -- waiting for player to accept or decline
            script.Disabled = true
            wait(2)
            text.Text = "BATTLE"
            script.Disabled = false
            return
        end
        if hasgui.Value == false then -- if localplayer has a request, another request can't be sent.
            print("False")
            if iswaiting.Value == false then
                text.Text = "Cancel"
                game.ReplicatedStorage.BoolTrueRemote:FireServer(localname) 
                sendmessage()
                return
            end
            if iswaiting.Value == true then
                text.Text = "Waiting!" -- waiting for player to accept or decline
                script.Disabled = true
                wait(2)
                text.Text = "BATTLE"
                script.Disabled = false
                return
            end
        end
    end
end)

function sendmessage() -- sends the request to player.
    game.ReplicatedStorage.RequestRemote:FireServer(player)
end

ServerScript

local changeRemote = Instance.new("RemoteEvent", game.ReplicatedStorage)
changeRemote.Name = "BoolTrueRemote"

local change2Remote = Instance.new("RemoteEvent", game.ReplicatedStorage)
change2Remote.Name = "BoolFalseRemote"

local declineRemote = Instance.new("RemoteEvent", game.ReplicatedStorage)
declineRemote.Name = "DeclineRemote"

local Decline = game.ReplicatedStorage.defaultDecline

local requestRemote = Instance.new("RemoteEvent", game.ReplicatedStorage)
requestRemote.Name = "RequestRemote"

local Request = game.ReplicatedStorage.DefaultRequest

local HasGui = Instance.new("RemoteEvent",game.ReplicatedStorage)
HasGui.Name = "GuiTrueRemote"

local HasNotGui = Instance.new("RemoteEvent",game.ReplicatedStorage)
HasGui.Name = "GuiFalseRemote"

requestRemote.OnServerEvent:Connect(function(plr, plr2)
    local msg = Request:Clone()
    local text = Instance.new("TextLabel")
    local playername = Instance.new("IntValue")
    playername.Value = plr.UserId
    playername.Name = "PlayerID"
    local box = msg:WaitForChild("MovingBox")
    text.Text = plr.Name .. " wants to battle you!"
    text.Size = UDim2.new(0.7,0,1,0)
    text.Position = UDim2.new(0,0,0,0)
    text.BackgroundTransparency = 1
    text.TextScaled = true
    text.TextWrapped = true
    print(plr)
    print(plr2)
    print(text.Text)
    msg.Parent = plr2:WaitForChild("PlayerGui")
    text.Parent = box
    playername.Parent = box

end)

declineRemote.OnServerEvent:Connect(function(plr, plr2)
    local msgs2 = Decline:Clone()
    print(plr)
    print(plr2)
    msgs2.Parent = plr2:WaitForChild("PlayerGui")
    local boolval = plr2:WaitForChild("WaitingForPlayer")
    boolval.Value = false

end)

changeRemote.OnServerEvent:Connect(function(plr)

    local boolvalue = plr:WaitForChild("WaitingForPlayer")
    boolvalue.Value = true

end)

change2Remote.OnServerEvent:Connect(function(plr)

    local boolvalue = plr:WaitForChild("WaitingForPlayer")
    boolvalue.Value = false

end)

HasGui.OnServerEvent:Connect(function(plr)

    local guiE = plr:WaitForChild("hasRequest")
    guiE.Value = true

end)

HasNotGui.OnServerEvent:Connect(function(plr)

    local guiE2 = plr:WaitForChild("hasRequest")
    guiE2.Value = false

end)

game.Players.PlayerAdded:connect(function(player)

    local bool = Instance.new("BoolValue", player)
    bool.Value = false
    bool.Name = "WaitingForPlayer"

    local bool2 = Instance.new("BoolValue", player)
    bool2.Value = false
    bool2.Name = "hasRequest"
end)