VM results apply:

+ Gas debit/refund addeded
+ GUI validation impl started

ethereumj-core/src/main/java/org/ethereum/core/Transaction.java

@@ -12,6 +12,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.spongycastle.util.BigIntegers;
 
+import java.math.BigInteger;
 import java.security.SignatureException;
 import java.util.Arrays;
 
@@ -154,6 +155,11 @@ public class Transaction {
         return gasLimit;
     }
 
+    // TODO: performance improve multiply without BigInteger
+    public BigInteger getTotalGasDebit(){
+        return new BigInteger(1, gasLimit).multiply(new BigInteger(1,gasPrice));
+    }
+
     public byte[] getData() {
         if (!parsed) rlpParse();
         return data;

ethereumj-core/src/main/java/org/ethereum/gui/ContractSubmitDialog.java

@@ -260,6 +260,9 @@ class ContractSubmitDialog extends JDialog implements MessageAwareDialog {
 
     public void submitContract(){
 
+        if (!validInput())
+            return;
+
         Transaction tx = null;
         try {
             tx = createTransaction();
@@ -304,6 +307,24 @@ class ContractSubmitDialog extends JDialog implements MessageAwareDialog {
         return tx;
     }
 
+
+    private boolean validInput() {
+
+        Account account = ((AccountWrapper)creatorAddressCombo.getSelectedItem()).getAccount();
+        BigInteger currentBalance = account.getState().getBalance();
+        BigInteger gasPrice = BigInteger.valueOf( MainData.instance.getBlockchain().getGasPrice());
+        BigInteger gasInput = new BigInteger( this.gasInput.getText());
+
+        boolean canAfford = currentBalance.compareTo(gasPrice.multiply(gasInput)) >= 0;
+
+        if (!canAfford){
+            alertStatusMsg("The address can't afford this transaction");
+            return false;
+        }
+        return true;
+    }
+
+
     public static void main(String args[]) {
 
         AccountState as = new AccountState();

ethereumj-core/src/main/java/org/ethereum/manager/WorldManager.java

@@ -115,6 +115,20 @@ public class WorldManager {
                 logger.info("running the init for contract: addres={}" ,
                         Hex.toHexString(tx.getContractAddress()));
 
+            // first of all debit the gas from the issuer
+            BigInteger gasDebit = tx.getTotalGasDebit();
+            senderState.addToBalance(gasDebit.negate());
+            if (senderState.getBalance().signum() == -1){
+                // todo: the sender can't afford this contract do Out-Of-Gas
+
+            }
+
+            if(stateLogger.isInfoEnabled())
+                stateLogger.info("Before contract execution the sender address debit with gas total cost, \n sender={} \n contract={}  \n gas_debit= {}",
+                         Hex.toHexString( tx.getSender() ),    Hex.toHexString(tx.getContractAddress()), gasDebit);
+            worldState.update(senderAddress, senderState.getEncoded());
+
+
             VM vm = new VM();
             Program program = new Program(initCode, programInvoke);
             vm.play(program);
@@ -129,8 +143,19 @@ public class WorldManager {
 
             // TODO: (!!!!!) ALL THE CHECKS FOR THE PROGRAM RESULT
 
-            if (bodyCode != null){
+            BigInteger gasPrice = BigInteger.valueOf( MainData.instance.getBlockchain().getGasPrice());
+            BigInteger refund =
+                    gasDebit.subtract(BigInteger.valueOf( result.getGasUsed()).multiply(gasPrice));
 
+            if (refund.signum() > 0){
+                if(stateLogger.isInfoEnabled())
+                    stateLogger.info("After contract execution the sender address refunded with gas leftover , \n sender={} \n contract={}  \n gas_refund= {}",
+                            Hex.toHexString(tx.getSender()) ,Hex.toHexString(tx.getContractAddress()), refund);
+                senderState.addToBalance(refund);
+                worldState.update(senderAddress, senderState.getEncoded());
+            }
+
+            if (bodyCode != null){
                 byte[] codeKey = HashUtil.sha3(bodyCode);
                 chainDB.put(codeKey, bodyCode);
                 receiverState.setCodeHash(codeKey);
@@ -148,7 +173,7 @@ public class WorldManager {
             if (receiverState.getCodeHash() != HashUtil.EMPTY_DATA_HASH){
 
                 byte[] programCode = chainDB.get(receiverState.getCodeHash());
-                if (programCode.length != 0){
+                if (programCode != null && programCode.length != 0){
 
                     Block lastBlock =
                             MainData.instance.getBlockchain().getLastBlock();

ethereumj-core/src/main/java/org/ethereum/vm/Program.java

@@ -368,6 +368,8 @@ public class Program {
             logger.debug(" -- MEMORY --  {}", memoryData);
             logger.debug(" -- STORAGE -- {}\n", storageData);
 
+            logger.debug("\n\n  Spent Gas: {}", result.getGasUsed());
+
 
             StringBuilder globalOutput = new StringBuilder("\n");
             if (stackData.length() > 0) stackData.append("\n");