What is it ?

I saw this flower on a bush by the side of the road when I was walking to my friends home today. I've no idea what flower this is and I've never seen one before but I found it very pretty and stopped to take a photo with my iphone. I hope someone recognises it and can tell me the name.
I went with a friend to a Kannada class today. It was only for generally spoken Kannada and was a lot of fun though I don't know how much I actually remember. I've another 4 hour class tomorrow afternoon.