Mining program not working: bios:337: [string "Mine"]:45:'=' expected

Title: Mining program not working… need help I'm pretty new to computer craft and I'm also quite new to coding, but I tried to write a program anyway. What is meant to happen is that the turtle is supposed to dig a 2x2 tunnel for 100 blocks, then place a chest (in slot 1 of the turtle) down and empty all of the loot into the chest. Here's the program:

function there()
  for i=1,10,1 do
        turtle.dig()
        turtle.forward()
        turtle.digUp()
  end
end

function mineBack()
  for i=1,99,1 do
        turtle.dig()
        turtle.forward()
        turtle.digUp()
  end
end

function back()
  if true then
        turtle.turnLeft()
        turtle.dig()
        turtle.forward()
        turtle.digUp()
        turtle.turnRight()
        if true do
          mineBack()
        end
  end
end

while turtle.getItemCount(1) > 0 do
  there()
  back()
  turtle.dig()
  turtle.select(1)
  turtle.forward()
  turtle.digUp()
  turtle.back()
  turtle.place()
  for i=2,16,1 do
        turtle.drop()
  end
  turtle.turnRight()
  for i=1,3,1 do
        turtle.dig()
        turtle.forward() --#This is line 45
        turtle.digUp()
  end
  turtle.turnRight()
end

The problem it's giving me is: bios:337: [string "Mine"]:45:'=' expected
This is a weird problem, because line 45 is: turtle.digUp(). I haven't managed to find any other problems because I don't
know how to fix this one.
If anyone can see a problem in my code, either by looking at it on this post, or opening it in a turtle and figuring out the problem, please respond with a suggestion or a new code to do the same thing I want done.
Thanks in advance! WRKAQARG, away!

Did you copy and paste this or retype it by hand?

Check out 'for loops' on the wiki.

for i = 1,5 do --do something 5 times
	<code>
end

Also have a look at 'while loops':

while true do
	<code>
end

campicus, on 16 September 2013 - 11:45 AM said:

-snip-

You should check those out too. Nothing's wrong with his for loops. The problem is on line 24 where he used 'do' instead of 'then'.

Line 24 would throw a 'then' expected, which leads me to suspect that this is retyped and that OP added parentheses to the function call on line 44 that aren't in the original code.

LBPHacker, on 16 September 2013 - 11:49 AM said:

campicus, on 16 September 2013 - 11:45 AM said:

-snip-

You should check those out too. Nothing's wrong with his for loops. The problem is on line 24 where he used 'do' instead of 'then'.

I stand corrected! I forgot all about being able to define the increments in for loops. Still, the 1 isn't need in those for loops.

I'm not sure I understand this:

if true then
  do something
end

Wouldn't that code always 'do something'?

campicus, on 17 September 2013 - 10:05 AM said:

-snip-

Debugging? And yeah, the 1 isn't needed; I just didn't like the way you indirectly stated that that was the problem.

LBPHacker, on 17 September 2013 - 10:12 AM said:

campicus, on 17 September 2013 - 10:05 AM said:

-snip-

Debugging? And yeah, the 1 isn't needed; I just didn't like the way you indirectly stated that that was the problem.

Debugging what? I don't understand sorry :s I just wanted to know the purpose of "if true then"
And yep, I was definitely wrong about the for loops, my bad.