function getRate() constant internal returns (uint256) {
        if      (block.timestamp < startline + 19 days) return tokenPrice.mul(138).div(100); 
        else if (block.timestamp <= startline + 46 days) return tokenPrice.mul(123).div(100); 
        else if (block.timestamp <= startline + 60 days) return tokenPrice.mul(115).div(100); 
        else if (block.timestamp <= startline + 74 days) return tokenPrice.mul(109).div(100); 
        return tokenPrice; 
    }