OK, let's go over a few things, and you'll probably have to answer a few questions for me.
1) Does the sunday class extend JFrame as well? Is the user interacting with this visual object and the results then are displayed in the results jframe? If so, do you have a sunday object displayed and finding that user interaction is not translating over to the results frame as expected? If so, you may have more than one sunday object, one visible, and one not visible, and unfortunately the invisible one is the one that results is interacting with.
2) I'm not very familiar with NetBeans, but I would guess that that when you set a property of a component such as a JLabel, the property will be set at the JLabel's creation time. This means that if you set your JLabel's text to equal the rslt String, it is likely being set up when the program is being initialized and
before any user has had a chance to interact with your program. I'm guessing that your JLabel's text needs to be set
dynamically during the running of your program. For that to happen, you could do:
a) create a public method in class results called something setLabel1Text(String text), i.e.:
public void setLabel1Text(String text)
{
jlabel1.setText(text);
}
b) pass a reference to your results class into your sunday class. This can be done either by a method or if results is the only location where sunday is created and displayed, then this could be done via the constructor, as I did in my example. Here is where you would pass a "this" object into sunday.
c) have sunday call this method whenever an event occurs that makes it want to change what results should display. One place to call this would be inside of a button's actionPerformed method within its ActionListener.
3) Make sure that there is only one sunday object and only one results object, and that the objects you expect to be dealing with each other are doing just that. You may want to sprinkle your code generously with some System.out.println("..."); where you print out your current location in the program and any key variable values, just to make sure that the code you think is being called is in fact being called. It's a primitive form of debugging.
BTW, Java naming convention dictates that classes should have their first letters capitalized. One reason this is important is so that others reading your code will more easily understand it.