I'm writing a very basic ERC20 token using solidity in the Mist wallet. For some reason the compiler doesn't like the totalSupply() function name. If I change this name it compiles fine. 

To be ERC20 compliant, this function has to be signed this way. 

How do I get around this error?

[![Solidity Code][1]][1]

[![enter image description here][2]][2]

  [1]: https://i.stack.imgur.com/Br0On.png
  [2]: https://i.stack.imgur.com/ghZqo.png