Added Limit of 50 Euro

WarpDrinkApp/app/src/main/java/ms/warpzone/warppay/manager/MainManager.java

@@ -357,6 +357,20 @@ public class MainManager {
     public void chargeAmount(double amount) {
 
         User currentUser = this.dataManager.getCurrentUser();
+        if(amount < 0) {
+            NotificationDialog ndTransfer = new NotificationDialog(MainManager.getInstance().getMainActivity());
+            ndTransfer.setWarning();
+            ndTransfer.setMessage("Error Charging your account");
+            ndTransfer.show(4000);
+            return;
+        }
+        if(currentUser.getCredit()+amount > 50) {
+            NotificationDialog ndTransfer = new NotificationDialog(MainManager.getInstance().getMainActivity());
+            ndTransfer.setWarning();
+            ndTransfer.setMessage("Maximal 50 Euro Guthaben erlaubt!");
+            ndTransfer.show(5000);
+            return;
+        }
         RestTransaction t = new RestTransaction();
         t.setAmount(amount);
         t.setTrans_type(1);