Limit problem involving a double factorial

1. Oct 11, 2014

powerof

1. The problem statement, all variables and given/known data

Solve the following limit:
$$\lim_{n\rightarrow \infty }n\cdot\left ( \frac{2\cdot4\cdot6 \cdots (2n-2)}{1\cdot3\cdot5\cdots (2n-1)} \right )^{2}$$
3. The attempt at a solution

I don't know where to begin. Until know I've encountered limits which I could deal with in some way but this is new for me. Any tips?