extracting string from uicontrol edit text gui upon callback without using another function

So here is my code:

          rQ = uicontrol('Style','text',...
                         'String','How many rules are needed?',...
                         'Position',[10 350 200 15]);
          rN = uicontrol('Style','edit',...
                         'Position',[10 300 200 15],...
                         'Callback','happy=1',...
                         'String','');
          ruleNum = str2double(get(rN,'String'))

When I run this current code, my GUI shows the static text and the edit textbox with nothing in it and in the command window it shows "ruleNum=NaN". When I do type a number in and press enter, it just shows "happy=1". What I want is for ruleNum to equal the number I type into the edit textbox and I want this to occur after I have typed in the number and pressed enter. I can't call another function like http://www.mathworks.com.au/matlabcentral/answers/51337-how-to-evaluate-calback-function-in-edit-text-uicontrol because my code is part of an IF statement.

Thanks in advance

[Michael Haderlein]

Actually, you have to call another function like shown in the link. Also, there's a further link to Matt's tutorial on guis which might be helpful for you.

What do you mean with "my code is part of an IF statement"? I don't think there's a case in which you cannot to this. You just need to figure out how to do it.

[Timothy]

Oh! I was under the assumption that I had to put the new function inside my current function. So I've added another function to the end of my current function and it works, thanks Michael! The code that I have posted is nested in an IF statement, that's what I meant.