Letter draw

-- Letter drawer --
Player = game.Players.LocalPlayer
Mouse = Player:GetMouse()
PlayerGui = Player:WaitForChild("PlayerGui")
Screen = Instance.new("ScreenGui",PlayerGui)
Screen.Name = "Letter Draw"
letters = {
    H = {
        [1]={1,0,0,0,0,0,1};
        [2]={1,0,0,0,0,0,1};
        [3]={1,0,0,0,0,0,1};
        [4]={1,1,1,1,1,1,1};
        [5]={1,0,0,0,0,0,1};
        [6]={1,0,0,0,0,0,1};
        [7]={1,0,0,0,0,0,1};
    }}
local Box = Instance.new("Frame",Screen)
Box.Position = UDim2.new(0.5,0,0.5,0)
Size = 7
PSize = 12
LastPos = UDim2.new(0,0,0,0)
Box.Size = UDim2.new(0,PSize*Size,0,PSize*Size)
Box.Position = UDim2.new(0.5,-(PSize*Size/2),0.5,-(PSize*Size/2))
Pixels = {}
for x = 0,Size-1 do
    for y = 0,Size-1 do
        local Pixel = Instance.new("Frame",Box)
        Pixel.BackgroundColor3 = Color3.new(1,1,1)
        Pixel.Size = UDim2.new(0,PSize,0,PSize)
        Pixel.Position = UDim2.new(0,x*PSize,0,y*PSize)
        Pixel.BorderSizePixel = 0
        table.insert(Pixels,{x=x+1,y=y+1,Pixel=Pixel})
    end
end
MD = false
Mouse.Button1Down:connect(function()
    MD = true
    LastPos = UDim2.new(0,0,0,0)
    while MD and wait() do
        for i,v in pairs(Pixels) do
            if Mouse.X > v.Pixel.AbsolutePosition.X and Mouse.Y > v.Pixel.AbsolutePosition.Y and Mouse.X < v.Pixel.AbsolutePosition.X+v.Pixel.AbsoluteSize.X and Mouse.Y < v.Pixel.AbsolutePosition.Y+v.Pixel.AbsoluteSize.Y then
                v.Pixel.BackgroundColor3 = Color3.new(0,0,0)
            end
        end
    end
end)
Mouse.Button1Up:connect(function() MD = false end)