Gas required exceeds limit: 3000000. - blockchain

Question

pragma solidity ^0.4.16;
contract createNewToken {
uint256 total_ether_to_send;
address private owner;
//constructor
function createNewToken() public{
owner = msg.sender;
}
// client request for tokens by sending ether.
function requestForToken() public payable{
address sender = msg.sender;
uint value = msg.value;
total_ether_to_send = value;
require(sender.balance >= total_ether_to_send);
owner.transfer(total_ether_to_send);
total_ether_to_send = value / 2;
require(owner.balance >= total_ether_to_send);
sender.transfer(total_ether_to_send);
}
}
I have written this code in solidity in Remix IDE. The contract was successfully created but when I used it, it gave me an error saying "Gas required exceeds limit: 3000000. An important gas estimation might also be the sign of a problem in the contract code. Please check loops and be sure you did not sent value to a non payable function". I don't have much code written but its still gave me this error. Can anyone help?

Answer 1

First, your msg.value is already sent to your method, hence you don't need to check senders balance: require(sender.balance >= total_ether_to_send);.
Second, you don't have a fallback function in your contract to receive ether.
Third, you are trying to send 100% msg.value to owner and then send 50% of msg.value back to sender. Obviously you cannot spend 150% of msg.value without any additional funds on your contract. Here is example of working code:
function requestForToken() public payable{
address sender = msg.sender;
uint value = msg.value;
total_ether_to_send = value / 2;
require(this.balance >= total_ether_to_send);
owner.transfer(total_ether_to_send);
require(this.balance >= total_ether_to_send);
sender.transfer(total_ether_to_send);
}
function() payable {}