Having Problems with my Mining Program

I have just recently started to write a vertical mining program, but it seems to have a bug with the function that I've made to check the walls for ores that are worthwhile (i.e. iron, coal, diamond, etc.). In this version of the code I'm not able to even get it to mine iron ore. Here's the pastebin: http://www.pastebin.com/UCuHTLc8 (some of the comments are wrong due to them being added prior to this version and not being fixed yet). Thank you for your help!

Take another look at the documentation for turtle.inspect(): It doesn't just return a string, it returns a boolean (indicating whether a block was found) followed by a table (contain information about that block, if one was present).

local function junk() --defines function
        local found, block = turtle.inspect()

        if found and block.name == "minecraft:iron_ore" then --determines if item is valuable
                turtle.dig()   
        end
end

To expand on what we consider "valuable", we might implement a lookup table of blocks we're interested in:

local treasure = {["minecraft:iron_ore"] = true, ["minecraft:gold_ore"] = true, ["minecraft:etc"] = true}

local function junk() --defines function
        local found, block = turtle.inspect()

        if found and treasure[block.name] then --determines if item is valuable
                turtle.dig()   
        end
end

I'm now getting a return of "bios:14 [string "mine"]:3: '}' expected", but as far as my eyes can see, it's fine, so it must be somewhere else in the code, but I can't find it, so I don't really know what to do…
pastebin: http://www.pastebin.com/BwcKAajF

My bad - I left out some square brackets, which I've now edited into my above post.

Thank you, it works perfectly now. So that means I'm going to mess it up even more to try and make it suit my needs as I don't play on vanilla usually! Again, thank you!