How can i change size of input from a layer (pool2) to another layer (norm2) when using Alexnet?

i am developing a face recognition application using Alexnet, but there happens to be an error when training the network. ("Layer 'pool2': Input size mismatch. Size of input to this layer is different from the expected input size.Inputs to this layer: from layer 'norm2' (2×2×256 output)"). so is there a way to change the expected input or output of one of the layers?