It’s actually quite difficult to get round a Doppler radar. We had a demonstration in our laboratory where I put I suppose it was a five pound note in a safe, and we had children coming in and we said, ‘There is this,’ they could see the five pound note, and we said, ‘If you can there without the alarm going off, you can have it.’ And of course there were queues of these ten, eleven year olds who were sure they could do it. And there was one almost did it, I will say, he almost did it. You could hardly see him moving. In fact, if you have a very sensitive one you can actually detect someone’s heartbeat in this way, just by the movements of their skin. And we had open days, for the population of Malvern, because they always had this big establishment of great mystery, and we were recruiting people, obviously a lot of people worked there, but we thought it very good that their families should now and then come in. So we would have an open day. I don’t think it was every year, but it certainly was fairly often, there’d be an open day and we’d put on exhibits so that they could see things. Most establishments used to have something like that. And certainly the open days were open to children, and this one, well I would say that this kid, you could hardly see him moving as he approached my five pound note, and I was getting quite nervous. But then he got excited, at the last minute, and you could see him thinking, I’ve done it, and he put his hand out quickly to grab the note, and of course the sudden movement set off the alarm. I think I gave him one pound.