I have a requirement as described in the attached screen shot. When blue add button is clicked, one more UItextfield have to be inserted between last text field
On add button add a textfeild in subview and give the textfeild a unique tag so it will help you to differentiate between all textfeilds. For setting frame take the reference of your last textfeild frame and accordingly set the y coordinate.
UITextField *textField = [[UITextField alloc] initWithFrame:yourFrame];
textField.delegate = self;
textField.tag=yourtag;
[scrollview addSubview:textField];
[textField release];//if arc is disable