ScriptUI run script from dialog button

Question

Here is what I have right now.  It is a little clunky in the way it works, and I would just like to make it a bit slicker.
I have a script on startup that creates a Menu item with a dropdown submenu item. when you click on the submenu item, it starts a script. 
The first thing the script does is pop up a message box that tells them that two dialog boxes are going to popup. The first one asking them to choose the location of an xml file and the second dialog box that ask them to choose the location of their image folder.  After they finish choosing their folder in the second dialog, the script takes those two values, makes them variables, and continues to run the rest of the script. 
Here is what I would like it to do..
1. open a dialog window with two input fields, two "browse" buttons, and OK and CANCEL buttons
2. when you click the first browse button next to the first input field, it will open a file dialog window.  You select your file and the file string will populate the input field
3. when you click the second button next to the second input field, it opens a folder dialog window.  You select the folder and the string populates the second input field.
4. when you click OK, it feeds the values in the input fields to a script.
I already have scripts to that open the file and folder dialogs, but what I can't figure out  how to do is to start and run a script from a button press, in this case, when the OK button is pressed.  It is probably an onClick, but I haven't been able to find any examples of what the syntax would be. 
The closest I have found is in the Beginning ScriptUI document that was on Jongware's site, in the section on Communication between windows.  But that opens each of the windows with a different script and not using a button press to call a script.
As always, any point in the right direction is very much appreciated. thanks.

Answer 1

Thanks Gotterman, but the issue I was having was that the dialogs I was opening were not being created by me.  They were more like OS generated windows.  So I am not able to give the window a name, or the input field a name in order to reference it.
Peters response was actually correct, although I did have to open the folder dialog a bit differently to get it to work.  I had to use a style that I got from Jongware in a previous thread, but the concept that Peter showed in the last post pointed me in the right direction. 
I just have one more piece to figure out, how I am going to pass the variables to another script, but I think that is something i will have to work out on my own.
For anyone who is curious, here is the code I came up, modifying and combining some of Peters examples from the book plus the help he gave me in this thread.  The alert after closing the dialog is just for testing to show that the values are being held by the variables so I can use them else where.
function mySnippet(){    
//<fragment>   
#target indesign;
#targetengine "session";
var w2 = new Window("palette", "Window 2", undefined, {resizeable: true});
var e2 = w2.add ("edittext"); e2.characters = 30;
var e3 = w2.add ("edittext"); e3.characters = 30;
var f2 = w2.add ("button", undefined,"Browse XML");              
var f3 = w2.add ("button", undefined,"Browse Folder");              
var f4 = w2.add ("button",undefined,"SAVE AND RUN");              
var tf              
var tfo                
f2.onClick = function()                {               
tf = File.openDialog("Select your XML File","*.xml");                    
if (tf != null)                    
e2.text = tf;                    
f3.onClick = function()                {              
var tfol = new Folder("~/My Documents")               
tfo = tfol.selectDlg("Get Folder");                    
if (tfo != null)                    
e3.text = tfo;                    
f4.onClick = function()               
w2.close();                   
alert ("xml value: " + tf  + "\nfolder value: " + tfo);                
w2.show();    
//</fragment>