function verifyStage()internal
    {
        if (stage==Stage.second&&Remain==0)
        {
            stage= Stage.secondreturn;
        }
        if (stage==Stage.firstreturn&&confirm2stage)
        {
             stage=Stage.second;
        }
        if (uint32(block.timestamp)> endtime&&Remain>10000000*10**9&&stage==Stage.first)
        {
            stage=Stage.fail;
        }
        if (uint32(block.timestamp)>= endtime&&stage==Stage.first)
        {
             stage=Stage.firstreturn;
        }
    }