constructor() public {
    
    airdroptoken = 0x6EA3bA628a73D22E924924dF3661843e53e5c3AA;
    token = AirdropToken(airdroptoken);
    tmptoken = AirdropToken(airdroptoken);
    icotoken = AirdropToken(airdroptoken);
    decimals = getDecimals();
    rate = 10000; 
  }