Index: src/components/org/apache/jmeter/assertions/gui/BeanShellAssertionGui.java
===================================================================
--- src/components/org/apache/jmeter/assertions/gui/BeanShellAssertionGui.java	(revision 1304244)
+++ src/components/org/apache/jmeter/assertions/gui/BeanShellAssertionGui.java	(working copy)
@@ -29,6 +29,7 @@
 import javax.swing.JTextField;
 
 import org.apache.jmeter.assertions.BeanShellAssertion;
+import org.apache.jmeter.gui.util.BeanShellTextArea;
 import org.apache.jmeter.testelement.TestElement;
 import org.apache.jmeter.testelement.property.BooleanProperty;
 import org.apache.jmeter.util.JMeterUtils;
@@ -43,7 +44,7 @@
 
     private JTextField parameters;// parameters to pass to script file (or script)
 
-    private JTextArea scriptField;// script area
+    private BeanShellTextArea scriptField;// script area
 
     public BeanShellAssertionGui() {
         init();
@@ -136,7 +137,7 @@
     }
 
     private JPanel createScriptPanel() {
-        scriptField = new JTextArea();
+        scriptField = new BeanShellTextArea();
         scriptField.setRows(4);
         scriptField.setLineWrap(true);
         scriptField.setWrapStyleWord(true);
Index: src/core/org/apache/jmeter/gui/util/BeanShellTextArea.java
===================================================================
--- src/core/org/apache/jmeter/gui/util/BeanShellTextArea.java	(revision 0)
+++ src/core/org/apache/jmeter/gui/util/BeanShellTextArea.java	(working copy)
@@ -0,0 +1,108 @@
+package org.apache.jmeter.gui.util;
+
+import java.awt.event.ActionEvent;
+import java.awt.event.KeyEvent;
+
+import javax.swing.AbstractAction;
+import javax.swing.JComponent;
+import javax.swing.JTextArea;
+import javax.swing.KeyStroke;
+import javax.swing.text.BadLocationException;
+import javax.swing.text.Document;
+
+public class BeanShellTextArea extends JTextArea {
+	private static final long serialVersionUID = -2943059989300009359L;
+
+	public BeanShellTextArea() {
+		super();
+		initListener();
+	}
+
+	private void initListener() {
+		registerKeyboardAction(new AutoIndentAction(), KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0), JComponent.WHEN_FOCUSED);
+	}
+	
+	/* from http://www.jroller.com/santhosh/entry/autoindent_for_jtextarea */
+	private class AutoIndentAction extends AbstractAction { 
+		private static final long serialVersionUID = 1476242317203366836L;
+
+		
+		public void actionPerformed(ActionEvent ae) { 
+	        JTextArea comp = (JTextArea)ae.getSource();
+	        Document doc = comp.getDocument(); 
+	 
+	        if(!comp.isEditable()) 
+	            return; 
+	        try {
+	        	int line = comp.getLineOfOffset(comp.getCaretPosition());
+	            int start = comp.getLineStartOffset(line);
+	            int end = comp.getLineEndOffset(line);
+	            String str = doc.getText(start, end - start);
+	            
+	            String whiteSpace = getLeadingWhiteSpace(str);
+	            
+	            if(str.contains("{") && !str.contains("}")){
+	            	whiteSpace += "\t";
+	            } else if(!str.contains("{") && str.contains("}")) {
+	            	whiteSpace = getMatchingWhitespace(comp, doc, line);
+	            	doc.remove(start, end - start);
+	            	doc.insertString(start, whiteSpace + str.trim(), null);
+	            }
+	            
+	            doc.insertString(comp.getCaretPosition(), '\n' + whiteSpace, null);
+	            
+	            
+	        } catch(BadLocationException ex) { 
+	            // ignore
+	        } 
+	    } 
+	 
+	    private String getMatchingWhitespace(JTextArea comp, Document doc, int line) {
+			int count = 0;
+	    	for(; line >= 0; line--) {
+				try {
+		            int start = comp.getLineStartOffset(line);
+		            int end = comp.getLineEndOffset(line);
+		            String str = doc.getText(start, end - start);
+					if (str.contains("{"))
+						count--;
+					if (str.contains("}"))
+						count++;
+					
+					if(count == 0) {
+						return getLeadingWhiteSpace(str);
+					}
+					
+				} catch(Exception e) {
+					// ignore
+				}
+			}
+	    	
+			return "";
+		}
+
+		/** 
+	     *  Returns leading white space characters in the specified string. 
+	     */ 
+	    private String getLeadingWhiteSpace(String str) { 
+	        return str.substring(0, getLeadingWhiteSpaceWidth(str)); 
+	    } 
+	 
+	    /** 
+	     *  Returns the number of leading white space characters in the specified string. 
+	     */ 
+	    private int getLeadingWhiteSpaceWidth(String str) { 
+	        int whitespace = 0; 
+	        while(whitespace<str.length()) { 
+	            char ch = str.charAt(whitespace); 
+	            if(ch==' ' || ch=='\t') 
+	                whitespace++; 
+	            else 
+	                break; 
+	        } 
+	        return whitespace; 
+	    }
+
+	} 
+	
+}