title: knockout compute sum
body: <p>I receive data from a WCF and bind it to a table. I have been helped in this forum to add some compute fields and everything works perfectly. I'd like to add a total at the footer of this table. a simple version of my page could be seen at <a href="http://jsfiddle.net/qeUHd/3/">http://jsfiddle.net/qeUHd/3/</a> . Basically I'd like to learn how to add a field to my ViewModel that's the result of sum of Another field in my sample "Amount". Any help would be greatly appreciated. 
  <a href="http://jsfiddle.net/qeUHd/3/">http://jsfiddle.net/qeUHd/3/</a></p>