- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {

    if (string.length == 0) {
        return YES;
    }
    NSInteger length = textField.text.length+string.length;

    if (textField == pharmacyPhone_TF2 || textField == prescriberNumber_TF ) {
        if (length < 12) {
            [AppInfo toggleViewState:continueBtn isEnabled:[self shouldEnableButton]];
        }
        else {
            [AppInfo toggleViewState:continueBtn isEnabled:[self shouldEnableButton]];
        }
    }


    if ((textField == tf_first_name || textField == tf_last_name ) && length>25 ) {
       return NO;
    }
    if(textField == tf_allergies && length >50 ){
        return NO;
    }
    return YES;


}