diff --git a/collects/htdch/draw/Canvas.java b/collects/htdch/draw/Canvas.java
index c1511384c1..96ed7219db 100644
--- a/collects/htdch/draw/Canvas.java
+++ b/collects/htdch/draw/Canvas.java
@@ -4,21 +4,34 @@ import geometry.*;
 import colors.*;
         
 public class Canvas {
-  private int width = 0; 
-  private int height = 0; 
+    private int width = 0; 
+    private int height = 0; 
 
-  public Canvas(int width, int height) { 
-   this.width = width; 
-   this.height = height; 
-  }
+    /** 
+     *@author Matthias Felleisen, Kathy Gray 
+     *@param width positive int, the width of the visible canvas 
+     *@param height positive int, the height of the visible canvas 
+     */ 
+    public Canvas(int width, int height) { 
+	this.width = width; 
+	this.height = height; 
+    }
     
-  // these two are cheats: 
-  protected native boolean copy();
-  protected native boolean stop();
+    // these two are cheats: 
+    protected native boolean copy();
+    protected native boolean stop();
     // I need to figure out how to accomplish these two things, especially stop,
     // directly at the Scheme level w/o going thru the Java layer.
      
     private boolean showing = false; 
+
+    /** 
+     *@return  true, if it can display a white canvas 
+     *The method initializes the canvas to a white area, 
+     *enables the drawing methods, and finally displays the canvas. If it
+     *succeeds, it produces <code>true</code>. Invoking the method a second
+     *time without calling <code>close</code> before has no effect.  
+     */
     public boolean show() { 
 	if (!showing) {
 	    xshow();
@@ -26,21 +39,78 @@ public class Canvas {
 	}
 	return true; 
     }
+
+    
+    /** 
+     *@return  true, if it can hide the canvas 
+     *The method hides the canvas and erases the current content. 
+     */
     public boolean close() { 
 	xclose(); 
 	showing = false; 
 	return true; 
     }
 	    
-  public native boolean xshow();
-  public native boolean xclose();
-  public native boolean drawCircle(Posn p, int r, AColor c);
-  public native boolean drawDisk(Posn p, int r, AColor c);
-  public native boolean drawRect(Posn p, int width, int height, AColor c);
-  public native boolean drawLine(Posn p0, Posn p1, AColor c);
-  public native boolean drawString(Posn p, String s);
-  public native boolean clearCircle(Posn p, int r, AColor c);
-  public native boolean clearDisk(Posn p, int r, AColor c);
-  public native boolean clearRect(Posn p, int width, int height, AColor c);
-  public native boolean clearLine(Posn p0, Posn p1, AColor c);
+    public native boolean xshow();
+    public native boolean xclose();
+
+    /** 
+     *@param p the center of the circle 
+     *@param r its radius
+     *@param c its outline color 
+     *@return true, if it can draw the circle into this canvas 
+     */
+    public native boolean drawCircle(Posn p, int r, AColor c);
+
+    /** 
+     *@param p the center of the disk 
+     *@param r its radius
+     *@param c its fill and outline color 
+     *@return true, if it can draw the disk into this canvas 
+     */
+    public native boolean drawDisk(Posn p, int r, AColor c);
+
+    /** 
+     *@param p the upper left of the rectangle 
+     *@param width positive int 
+     *@param height positive int 
+     *@param c its outline color 
+     *@return true, if it can draw the rectangle into this canvas 
+     */
+    public native boolean drawRect(Posn p, int width, int height, AColor c);
+
+    /** 
+     *@param p0 the first point on the line 
+     *@param p1 the second point on the line 
+     *@param c its color 
+     *@return true, if it can draw the line into this canvas 
+     */
+    public native boolean drawLine(Posn p0, Posn p1, AColor c);
+
+    /** 
+     *@param p the position of the baseline of the string 
+     *@param s the message to be drawn 
+     *@return true, if it can draw the string into this canvas 
+     */
+    public native boolean drawString(Posn p, String s);
+
+    /** 
+     *@return true, if it can erase the specified circle from this canvas 
+     */
+    public native boolean clearCircle(Posn p, int r, AColor c);
+
+    /** 
+     *@return true, if it can erase the specified disk from this canvas 
+     */
+    public native boolean clearDisk(Posn p, int r, AColor c);
+
+    /** 
+     *@return true, if it can erase the specified rectangle from this canvas 
+     */
+    public native boolean clearRect(Posn p, int width, int height, AColor c);
+
+    /** 
+     *@return true, if it can erase the specified string from this canvas 
+     */
+    public native boolean clearLine(Posn p0, Posn p1, AColor c);
 }