function airdrppReward()
        private
        returns(string){
        
        if(airdrop() == false){
            return "非常遗憾！没有空投！";
        }
        else{
            if(selfvoteamount[msg.sender] <= 1 ether && rounds[roundid].pot >= 0.1 ether){
              
              selfpotprofit[msg.sender] =  selfpotprofit[msg.sender].add(0.1 ether);        }
              
              rounds[roundid].pot = rounds[roundid].pot.sub(0.1 ether);
              
              return "恭喜获得空投 0.1 ether";
             }
            if(1 ether < selfvoteamount[msg.sender] && selfvoteamount[msg.sender] <= 5 ether && rounds[roundid].pot >=0.5 ether){
              
              selfpotprofit[msg.sender] = selfpotprofit[msg.sender].add(0.5 ether);
              
              rounds[roundid].pot = rounds[roundid].pot.sub(0.5 ether);
              
              return "恭喜获得空投 0.5 ether";
            }
            if(selfvoteamount[msg.sender] > 5 ether && rounds[roundid].pot >= 1 ether){
              
              selfpotprofit[msg.sender] = selfpotprofit[msg.sender].add(1 ether);
              
              rounds[roundid].pot = rounds[roundid].pot.sub(1 ether);
              
              return "恭喜获得空投 1 ether";
            }
    }