Multiple Instances Object Calling Getting #1009 Error

Question

Hi,
I believe this has to be a logical explanation for this. I have the code here as follows:
private function action():void{
    thematicMap.passBox(canvas,regions);
    thematicMap.drawthematicMap.passBox(canvas);  
    //Setting the Canvas
    thematicMap.setCanvas(0,0,30,50);     
    thematicMap.drawthematicMap.draw(regions);
    thematicMap.setCanvas(24,24,453,455);
    thematicMap.drawthematicMap.draw(regions);     
This does show two instances of the thematicMaps, which is what works in main.zip. However, what I really want to do is this:
private function action():void{
    thematicMap.passBox(canvas,regions);
    thematicMap.drawthematicMap.passBox(canvas); 
               a = new ThematicMap();
   b = new ThematicMap();  
    //Setting the Canvas
    a.setCanvas(0,0,30,50);
                b.setCanvas(24,24,453,455);     
               //Draw
              a.drawthematicMap.draw(regions);
  b.drawthematicMap.draw(regions);     
The output of the application below is only a blank screen. I then investigated and added some try and catch clauses to see what errors there are,
try {
         //Setting the Canvas
     a.setCanvas(0,0,30,50);     
     b.setCanvas(24,24,453,455); 
              catch (errObject:Error) {Alert.show("An error occurred: " + errObject.message);}
The results I got was Error #1009. How come that I have provided the parameters and the return is null object of reference?
Thanks for your help.
Alice

Answer 1

To answer your second point regarding if I had added a child to my  canvas to draw, here is the snippet:
public function draw(arr:Array):void{
             regions = arr;    
             component_width = [];
             component_height= [];       
             for (var s:String in regions) {
                trace("\n" + s);
                shape = new UIComponent();  
                gr = shape.graphics;
                gr.lineStyle(3);//Define line style  
                coords = regions[s];
                gr.moveTo(coords[0],coords[1]);               
             for (var i:int = 2; i < coords.length; i += 2) gr.lineTo(coords[i],coords[i + 1]);  
                 trace(coords);                
                 gr.lineTo(coords[0],coords[1]);    //return the code back to the beginning   
                 gr.endFill(); //Put this in if there is a color
                 canvas.addChild(shape);             
This is what is in my setCanvas function:
public function setCanvas(x:Number,y:Number,width:Number,height:Number):void{       
            canvas.setActualSize(width,height);
            canvas.x = x;
            canvas.y = y;  
            coordinate_conversion(regions);
            new_coordinate_conversion(regions);
What else could be wrong here?
Thanks for your help.
Alice