InsertSort.lua

function insertSort(a)
   for j=1, table.maxn(a) do
      key = a[j]
      i = j-1
      while i>=1 and a[i]>key do
	 a[i+1] = a[i]
	 i = i-1
      end
      a[i+1] = key
   end

end

a={2,1}
insertSort(a)
print(table.concat(a,',',1))