By Marja Novak LJUBLJANA/VELIKI OBREZ, Slovenia (Reuters) - Slovenia began erecting a razor wire fence along parts of its border with Croatia on Wednesday, saying it wanted better control over a tide of migrants flowing through the tiny country en route to other areas of Europe. The continent is grappling with its biggest influx of migrants - more than one million are expected this year - since World War Two and is deeply split over how best to respond. Around 180,000 people, many fleeing war in Syria and Afghanistan, have streamed into Slovenia since mid-October after trekking northwards along a Balkan corridor from Greece, most of them bound ultimately for Austria and then Germany.