random "tile" around a position

function love.load()
    tiles = { --random map with the "tiles"
        {0,0,0,0,0},
        {0,0,0,0,0},
        {0,0,0,0,0},
        {0,0,0,0,0},
        {0,0,0,0,0},
    }

    mouselock = false -- you can ignore this mouse lock stuff, its just a trick i use to force a single click...

    function random(mx,my)
        local x1 = math.random(-1,1) --random function to get the x variation
        local x2 = math.random(-1,1) --random function to get the y variation

        local rmx = mx+x1
        local rmy = my+x2

        -- some checks to not crash the code with a outside position
        if rmx < 1 then rmx = 1 end
        if rmx > 5 then rmx = 5 end
        if rmy < 1 then rmy = 1 end
        if rmy > 5 then rmy = 5 end

        return rmx,rmy
    end
end

function love.update()
    if love.mouse.isDown(1) and not mouselock then -- random stuff is triggered with a mouse click
        mouselock = true

        local mx,my = love.mouse.getPosition() -- using the mouse position as the center
        mx = math.floor(mx/160)+1 -- converting mouse x to a map coordenate
        my = math.floor(my/120)+1 -- converting mouse y to a map coordenate

        tiles[my][mx] = 1 -- changing the center red to visualize the origin

        local rmx,rmy = random(mx,my) --function gets the mouse coordenate, and return a valid random position around it

        tiles[rmy][rmx] = 2 -- changing a random tile around the center
    end

    function love.mousereleased()
        mouselock = false
    end
end

function love.draw()
    local x,y = 0,0
    for j=1,5,1 do
        for i=1,5,1 do
            if tiles[j][i] == 0 then -- empty "tile"
                love.graphics.setColor(1,1,1)
                love.graphics.rectangle("fill",x,y,160,120)
                love.graphics.setColor(0,0,0)
                love.graphics.rectangle("line",x,y,160,120)
            end
            if tiles[j][i] == 1 then -- center "tile"
                love.graphics.setColor(1,0,0)
                love.graphics.rectangle("fill",x,y,160,120)
                love.graphics.setColor(0,0,0)
                love.graphics.rectangle("line",x,y,160,120)
            end
            if tiles[j][i] == 2 then -- random generated "tile"
                love.graphics.setColor(0,0,1)
                love.graphics.rectangle("fill",x,y,160,120)
                love.graphics.setColor(0,0,0)
                love.graphics.rectangle("line",x,y,160,120)
            end
            x = x+160
        end
        x = 0
        y = y+120
    end
end