diff --git a/src/de/dhbwstuttgart/syntaxtree/statement/Expr.java b/src/de/dhbwstuttgart/syntaxtree/statement/Expr.java
index e62b9c533..f625c9ed0 100755
--- a/src/de/dhbwstuttgart/syntaxtree/statement/Expr.java
+++ b/src/de/dhbwstuttgart/syntaxtree/statement/Expr.java
@@ -4,8 +4,11 @@ package de.dhbwstuttgart.syntaxtree.statement;
 // ino.module.Expr.8630.import 
 import java.util.Hashtable;
 import java.util.Iterator;
-import de.dhbwstuttgart.typeinference.Menge;
 
+import org.apache.bcel.generic.ClassGen;
+import org.apache.bcel.generic.InstructionList;
+
+import de.dhbwstuttgart.typeinference.Menge;
 import de.dhbwstuttgart.myexception.CTypeReconstructionException;
 import de.dhbwstuttgart.myexception.SCStatementException;
 import de.dhbwstuttgart.syntaxtree.Class;
@@ -109,5 +112,7 @@ public abstract class Expr extends ExprStmt
     public ConstraintsSet TYPEStmt(TypeAssumptions assumptions){
     	throw new NotImplementedException(); //wird die TYPEStmt-Methode innerhalb einer Expr aufgerufen, dann ist etwas schief gelaufen.
     }
+    
+    public abstract InstructionList genByteCode(ClassGen _cg);
 }
 // ino.end
diff --git a/src/de/dhbwstuttgart/syntaxtree/statement/Null.java b/src/de/dhbwstuttgart/syntaxtree/statement/Null.java
index 5cac43a35..f69eaa273 100755
--- a/src/de/dhbwstuttgart/syntaxtree/statement/Null.java
+++ b/src/de/dhbwstuttgart/syntaxtree/statement/Null.java
@@ -5,6 +5,8 @@ package de.dhbwstuttgart.syntaxtree.statement;
 import java.util.Hashtable;
 
 import org.apache.bcel.generic.ClassGen;
+import org.apache.bcel.generic.InstructionFactory;
+import org.apache.bcel.generic.InstructionList;
 
 import de.dhbwstuttgart.typeinference.Menge;
 import de.dhbwstuttgart.logger.Logger;
@@ -91,10 +93,14 @@ public class Null extends Literal
 	}
 
 	@Override
-	public void genByteCode(ClassGen _cg) {
-		// TODO Auto-generated method stub
+	public InstructionList genByteCode(ClassGen cg) {
+		InstructionFactory _factory = new InstructionFactory(cg, cg.getConstantPool());
+		InstructionList il = new InstructionList();
 		
+		il.append(_factory.ACONST_NULL);
+		
+		return il;
 	}
-
+	
 }
 // ino.end
diff --git a/src/de/dhbwstuttgart/syntaxtree/statement/Return.java b/src/de/dhbwstuttgart/syntaxtree/statement/Return.java
index 0e5139964..7cef4cf9a 100755
--- a/src/de/dhbwstuttgart/syntaxtree/statement/Return.java
+++ b/src/de/dhbwstuttgart/syntaxtree/statement/Return.java
@@ -134,8 +134,10 @@ public class Return extends Statement
 
 	@Override
 	public InstructionList genByteCode(ClassGen cg) {
+		InstructionList il = retexpr.genByteCode(cg);
+		
 		InstructionFactory _factory = new InstructionFactory(cg, cg.getConstantPool());
-		InstructionList il = new InstructionList();
+		
 		il.append(_factory.createReturn(org.apache.bcel.generic.Type.VOID));
 		//TO BE DONE