if (mFrame.script) mContext->fp = mFrame.down;
AutoPushJSContext::~AutoPushJSContext(){    if(mContextStack)    {#ifdef DEBUG        JSContext* cx;        nsresult rv = mContextStack->Pop(&cx);        NS_ASSERTION(NS_SUCCEEDED(rv) && cx == mDebugCX, "unbalanced stack usage");#else        mContextStack->Pop(nsnull);#endif        NS_RELEASE(mContextStack);    }}