why is sendTransaction is taking too much gas?

Question

I have a contract such

contract tokenEvents
{
    event globalEvent(address contractAddress, string eventName, uint value);
    event globalEvent2(address contractAddress, string eventName, uint value, address senderAddress);

    function callEvent(string eventName, uint value)
    {
        globalEvent(msg.sender, eventName, value);
    }

    function callEvent2(string eventName, uint value, address senderAddress)
    {
        globalEvent2(msg.sender, eventName, value, senderAddress);
    }

}

Another contract is used to above contract such

function(){
    uint amount = msg.value;
    amountRaised += amount;
    tokenEvents te = tokenEvents(0x5488845db957f6fd3691b0c2959b607dc52f09b2); 
    uint nValue;
    address senderAddress;

    if (msg.sender == partyone){
        if (contribution[partyone] == 0)
        {
            contribution[partyone] = amount;
        }
        else
        {
            contribution[partyone] += amount;
        }

        eventName = "party1_contribution";
        nValue = contribution[partyone];
        senderAddress = partyone;

    }
    else if (msg.sender != beneficiary) {
        partytwo = msg.sender;
        if (contribution[partytwo] == 0){
            contribution[partytwo] = amount;
        } else {
            contribution[partytwo] += amount;
        }

        eventName = "party2_contribution";
        nValue = contribution[partytwo];
        senderAddress = partytwo;
    } 
    else {
        if (contribution[msg.sender] == 0){
            contribution[msg.sender] = amount;
        } else {
            contribution[msg.sender] += amount;
        }

        eventName = "other_contribution";
        nValue = contribution[msg.sender];
        senderAddress = msg.sender;
    }

    te.callEvent2(eventName, nValue, senderAddress);
}

Now whenever I send ether some ether to this contract its taking too much gas. For example: 20000

What is the issue?

Answer 1

21000 gas is the gas needes for a standard, non-contract transaction. You need to increase the gas based on how much computation is done.

All gas is refunded, so the simplest way to see how much gas is used is make the transaction with 100k gas, go to the TX on etherscan, and see how much gas it ended up using. In the future you can use that amount.

(How do I know how much gas to use when calling a contract?)