function __callback(bytes32 myid, string result) {
        if (msg.sender != oraclize_cbAddress()) {
            
            revert();
        }
        
        Tokens(result,1);
        
         if (userqueryID[myid] == myid) {
        
           one_ether_usd_price = stringToUint(result);
           
     
        uint no_of_tokens = ((one_ether_usd_price * uservalue[userAddress[myid]]) )  / (one_token_price * 10**22); 
         if (balanceOf(address(this)) > no_of_tokens) {

        
        balances[address(this)] -= no_of_tokens;
        balances[userAddress[myid]] += no_of_tokens;
        check_array_add(userAddress[myid]);
        Message("transferred to",userAddress[myid],no_of_tokens);
         }
         else
         revert();
    }
    }