I have a canvas element defined statically in the html with a width and height. If I attempt to use JavaScript to resize it dynamically (setting a new width and height - either on the attributes of the canvas or via the style properties) I get the following error in Firefox: uncaught exception: [Exception... "Illegal operation on WrappedNative prototype object" nsresult: "0x8057000c (NS_ERROR_XPC_BAD_OP_ON_WN_PROTO)" location: "JS frame :: file:///home/russh/Desktop/test.html :: onclick :: line 1" data: no] Is it possible to resize this element or do I have to destroy it and create a new element on the fly?