diff --git a/src/main/java/fucoin/AbstractNode.java b/src/main/java/fucoin/AbstractNode.java
index 7b7f943c10982101fddc28c673a24319fbc02d19..5b582932131d088bc1f52e379cb6662d30fe7f4d 100644
--- a/src/main/java/fucoin/AbstractNode.java
+++ b/src/main/java/fucoin/AbstractNode.java
@@ -181,10 +181,40 @@ public abstract class AbstractNode extends UntypedActor implements Serializable
      * @return Array[snapshot folder name, path to snapshot include filename]
      */
     private String[] getSnapshotDirAndFilename(String name, LocalDateTime time) {
-        String folder = time.getYear() + "-" + time.getMonthValue() + "-" + time.getDayOfMonth() + " " +
-                time.getHour() + "." + time.getMinute() + "." + time.getSecond();
+    	String folder = getFolderName(time);
         return new String[]{folder, "snapshots/" + folder + "/" + name + ".json"};
     }
+    
+    private String getFolderName(LocalDateTime time) {
+     	String result = "";
+     	
+     	String year = String.valueOf(time.getYear());
+     	String month = String.valueOf(time.getMonthValue());
+     	if(month.length()==1) {
+     		month = "0" + month;
+     	}
+     	String day = String.valueOf(time.getDayOfMonth());
+     	if(day.length()==1) {
+     		day = "0" + day;
+     	}
+     	String hour = String.valueOf(time.getHour());
+     	if(hour.length()==1) {
+     		hour = "0" + day;
+     	}
+     	String minute = String.valueOf(time.getMinute());
+     	if(minute.length()==1) {
+     		minute = "0" + minute;
+     	}
+     	String second = String.valueOf(time.getSecond());
+     	if(second.length()==1) {
+     		second = "0" + second;
+     	}
+     	
+     	result = year + "-" + month + "-" + day + "_"
+     			+ hour + "-" + minute + "-" + second;
+     	
+     	return result;
+     }
 
     private Statistics statistics = new Statistics();
 
diff --git a/src/main/java/fucoin/gui/WalletGuiControlImpl.java b/src/main/java/fucoin/gui/WalletGuiControlImpl.java
index 7ceecb14f99b1a6f4095a8c71ae9911ba1970e18..fac84c0e4ebfe6672564b52c7413da50cabca3af 100644
--- a/src/main/java/fucoin/gui/WalletGuiControlImpl.java
+++ b/src/main/java/fucoin/gui/WalletGuiControlImpl.java
@@ -12,6 +12,7 @@ import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.util.Enumeration;
 import java.util.Set;
+import java.text.NumberFormat;
 
 public class WalletGuiControlImpl implements WalletGuiControl {
 
@@ -27,7 +28,7 @@ public class WalletGuiControlImpl implements WalletGuiControl {
     private JLabel lblSendTo = new JLabel("Send to:");
     private JComboBox<String> txtSendTo = new JComboBox<>();
     private JLabel lblSendAmount = new JLabel("Amount:");
-    private JTextField txtSendAmount = new JTextField("");
+    private JTextField txtSendAmount = new JFormattedTextField(NumberFormat.getNumberInstance());
     private JButton btnSend = new JButton("Send");
     private JButton btnSearch = new JButton("Search");
     private JButton btnStore = new JButton("Store");
@@ -146,8 +147,13 @@ public class WalletGuiControlImpl implements WalletGuiControl {
         window.setVisible(true);
 
         btnSend.addActionListener(e -> {
-            wallet.send(txtSendTo.getSelectedItem().toString(),
-                    Integer.parseInt(txtSendAmount.getText()));
+        	String sendAmount = txtSendAmount.getText();
+        	if(sendAmount.trim().equalsIgnoreCase("")) {
+        		JOptionPane.showMessageDialog(new JFrame("Warning"), "You need to type a number of coins to send.");
+        	} else {
+        		wallet.send(txtSendTo.getSelectedItem().toString(),
+        				Integer.parseInt(sendAmount));
+        	}
         });
 
         btnStore.addActionListener(e -> {