Help with iphone dev - beyond error

I am just learning iphone development so please forgive me for what is probably a beginner's mistake. I've searched around and didn't find anything specific about my problem, so hopefully this is a simple solution.

The book provides examples of building a table from data hard-coded through an array. Unfortunately it never talks about how to get the data from the url, so I had to see what was going on and this is where my problems come in.

When I debug xcode the count seems to be correct, so I don't understand why it is out of bounds?

This error message:

2010-05-03 12:50:42.705 Simple Table[3310:20b] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSCFArray objectAtIndex:]: index (1) beyond bounds (0)'

      

        
        
        
      

    

My url returns the following string:

first,second,third,fourth

      

        
        
        
      

    

And here is the iphone code with an example of how the book works, commented out

#import "Simple_TableViewController.h"

@implementation Simple_TableViewController
@synthesize listData;

- (void)viewDidLoad
{
    /*
     //working code from book
     NSArray *array = [[NSArray alloc] initWithObjects:@"Sleepy", @"Sneezy", @"Bashful", @"Bashful", @"Happy",
                      @"Doc", @"Grumpy", @"Thorin", @"Dorin", @"Norin", @"Ori", @"Balin", @"Dwalin", @"Fili", @"Kili", @"Oin", 
                      @"Gloin", @"Bifur", @"Bofur", @"Bombur", nil];
     self.listData = array;
     [array release];
     */

     //code from interwebz that crashes 
     NSString *urlstr = [[NSString alloc] initWithFormat:@"http://www.mysite.com/folder/iphone-test.php"];
     NSURL *url = [[NSURL alloc] initWithString:urlstr];
     NSString *ans = [NSString stringWithContentsOfURL:url];
     NSArray *listItems = [ans componentsSeparatedByString:@","];

     self.listData = listItems;

     [urlstr release];
     [url release];
     [ans release];
     [listItems release];


    [super viewDidLoad];
}

- (void)didReceiveMemoryWarning {
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];

    // Release any cached data, images, etc that aren't in use.
}

- (void)viewDidUnload 
{
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
    self.listData = nil;
    [super viewDidUnload];
}


- (void)dealloc 
{
    [listData release];
    [super dealloc];
}

#pragma mark -
#pragma mark Table View Data Source Methods

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self.listData count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *SimpleTableIdentifier = @"SimpleTableIdentifier";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:SimpleTableIdentifier];

    if (cell == nil)
    {
        cell = [[[UITableViewCell alloc]
                 initWithStyle:UITableViewCellStyleDefault reuseIdentifier:SimpleTableIdentifier] autorelease];
    }

    NSUInteger row = [indexPath row];
    cell.textLabel.text = [listData objectAtIndex:row];
    return cell;
}

@end