Error in int and tuple connection
<p>I get this error:</p>

<pre><code>TypeError: unsupported operand type(s) for +=: 'int' and 'tuple' 
Line 37
http://pastebin.com/LhMS9Xhx

filter = [[1,1,1],[1,1,1],[1,1,1]]
activefield = [[1,2,3],[4,5,6],[7,8,9]]
newvalue = 0
newvalue+= filter[iii][jjj]*aktuellesFeld[iii][jjj]
</code></pre>
