Unable to remove dynamically created UIButton inside for loop - ios

Question

I am working on an app where the contacts phone numbers are listed depending on the number of phone numbers stored for the contact. I need a button corresponding to every phone number. I have written a for loop with an if condition
Now when user taps on a contact with 3 numbers the button is shown perfectly then he presses back button and goes to a contact with 1 number and still all the three buttons are showed.
I have tried [btn autorelease]; [btn setEnabled:NO]; [btn removeFromSuperView];
but still the problem isn't resolved. Below is the snipped of code :
for (int i=0;i<ABMultiValueGetCount(lMap);i++) {
if (i==0) {
// UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(230,110,88,35); //The position and size of the button (x,y,width,height)
[btn setTitle:#"SMS" forState:UIControlStateNormal];
[btn addTarget:self
action:#selector(showAbout)
forControlEvents:(UIControlEvents)UIControlEventTouchUpInside];
[self.view addSubview:btn];
[btn autorelease];
}
else if (i==1) {
// UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(230,150,88,35); //The position and size of the button (x,y,width,height)
[btn setTitle:#"SMS" forState:UIControlStateNormal];
[btn addTarget:self
action:#selector(showAbout)
forControlEvents:(UIControlEvents)UIControlEventTouchUpInside];
[self.view addSubview:btn];
[btn autorelease];
}
else if (i==2) {
// UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(230,190,88,35); //The position and size of the button (x,y,width,height)
[btn setTitle:#"SMS" forState:UIControlStateNormal];
[btn addTarget:self
action:#selector(showAbout)
forControlEvents:(UIControlEvents)UIControlEventTouchUpInside];
[self.view addSubview:btn];
[btn autorelease];
}

Answer 1

This should work.
// Declare a constant
int buttonTagConstant = 200;
// Before creating the buttons, delete the old ones first.
for (UIView* subV in self.view.subviews)
{
if ([subV isKindOfClass:[UIButton class]] && subV.tag == buttonTagConstant)
{
[subV removeFromSuperview];
}
}
int y_of_the_button = 110;
// Also I refactored your code as below
for (int i=0;i<ABMultiValueGetCount(lMap);i++)
{
btn.frame = CGRectMake(230, y_of_the_button, 88, 35); //The position and size of the button (x,y,width,height)
[btn setTitle:#"SMS" forState:UIControlStateNormal];
[btn addTarget:self action:#selector(showAbout) forControlEvents:(UIControlEvents)UIControlEventTouchUpInside];
btn.tag = buttonTagConstant;
[self.view addSubview:btn];
y_of_the_button += 40;
}