OOP: Chapter 3 Question

[stickbook41]

No: HPFGUIDX 61590

Happy Harry Weekend everybody!

I've just started my re-read and I have a question--sorry if it's 
been asked yet, I haven't had time to catch up on the flood of posts 
since the list opened *three hours* ago :)

In Chapter 3 (page 47, US), the first thing we hear Tonks (whom I 
LOVE) say is "Wotcher, Harry."

If I recall correctly, she (or maybe someone else) says it again 
later in the book.

What is "Wotcher"?  It doesn't seem to be anybody's name--is it UK 
slang?

Cheers!

-stickbook
who nearly lost it when Dumbledore cried