title: Just use one variable
body: <p>Can I use Tensorflow in DNN by only use one "W" as my weight if I have 3 hidden layer?
  I saw that other guys code use "W1","W2","W3" as their weight variables to compute forward propagation
  I mean for the input layer to first hidden layer I use "W", and first hidden layer to second hidden layer I use "W", too, but I let my "W" become other dimension(like "W2") to compute.
  Can I doing this?</p>