iOS 5 - Change thumbnail of a table view cell on touch - ios5

Question

So I'm trying to build here some kind of a to-do list - I have a table view, and on each cell I have a thumbnail which represents a checkbox. On touch, I want it to change images - from full to empty and vice versa. What I'm doing wrong? Here's some code :
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"taskCell";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
// Configure the cell...
UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(5, 5, 32, 32)];
[button addTarget:self action:#selector(checkmarkPressed:) forControlEvents:UIControlEventTouchUpInside];
[button setImage:[UIImage imageNamed:#"checkbox_empty"] forState:UIControlStateNormal];
[button setTag:101];
[cell addSubview:button];
[cell setIndentationWidth:36];
[cell setIndentationLevel:1];
cell.textLabel.text = [[self.appDel.allTasks objectAtIndex:indexPath.row] taskName];
return cell;
}
- (void) checkmarkPressed:(UIButton *)sender{
if(sender.tag == 101){
UITableViewCell *cell = ((UITableViewCell*)[sender superview]);
NSLog(#"Cell %i", [self.tableView indexPathForCell:cell].row);
UIImage *empty = [[UIImage alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"checkbox_empty" ofType:#"png"]];
UIImage *full = [[UIImage alloc] initWithContentsOfFile:[[NSBundle mainBundle] pathForResource:#"checkbox_full" ofType:#"png"]];
if ([sender imageView].image == [UIImage imageNamed:#"checkbox_empty"]) {
[sender setImage:full forState:UIControlStateNormal];
[self.tableView reloadData];
}
if ([sender imageView].image == full) {
[sender setImage:empty forState:UIControlStateNormal];
[self.tableView reloadData];
}
}
}

Answer 1

If you just want to change the image on touch , you can try this code
- (void) checkmarkPressed:(UIButton *)tempButton{
if (tempButton.tag == 101) {
tempButton.tag = 104;
[sender setImage:full forState:UIControlStateNormal];
}
else if (tempButton.tag == 104) {
tempButton.tag = 101;
[sender setImage:empty forState:UIControlStateNormal];
}
[self.tableView reloadData];
}

Answer 2

Found the solution :
if ([sender imageView].image == [UIImage imageNamed:#"checkbox_empty"]) {
[sender removeFromSuperview];
[sender setImage:full forState:UIControlStateNormal];
[[sender superview] addSubview:sender];
[self.tableView reloadData];
}
else if ([sender imageView].image == [UIImage imageNamed:#"checkbox_full"]) {
[sender removeFromSuperview];
[sender setImage:empty forState:UIControlStateNormal];
[[sender superview] addSubview:sender];
[self.tableView reloadData];
}