attempt to concatenate string and nil

I have a problem with my api when I go to use a few functions…

here is the api. http://pastebin.com/zYeRnCZb

the problem is when I use the startLoc() function and then the getLoc() function and I try to print the facing variable to the screen it gives me the attempt to concatenate string and nil error.

Here is and example of a basic program using those function and where I get the error.

t.getLoc()
print("I am here"..x..","..y..","..z..". Facing"..facing)
t.tl()
t.getLoc()
print("I am now facing"..facing)
t.tl()
t.getLoc()
print("I am now facing"..facing)
t.tl()
t.getLoc()
print("I am now facing"..facing)
t.tle()
t.getLoc()
print("I am now facing"..facing)

The error happens
test:2: attempt to concatenate string and nil

thanks for any help

You need to assign the values from getLoc to the variables x, y, z and facing.

x, y, z, facing = t.getLoc()

Is this in the program or the api?

Oh, Nevermind. I tried both….Its the program…Thanks for the help. I really appreciate it!