Open browser window function with additional attributes/behaviors

Question

Just let me say, writing JavaScript is not my forte. Having said that I am comfortable using JavaScript functions.
I have a need for a single JavaScript function that does several things. The script will be called from within a Captivate project. (If you are familiar with Captivate, you know that the JavaScript call needs to be a single string with no spaces or breaks.)
The script will be used as a Captivate “click box” behavior to open a URL in a window on top of the main (Captivate) project. There may be multiple click boxes present at the same time (in the Captivate Project).
Here is what the script needs to do:
1)    Open a new browser window of a specific size with specific browser attributes. (This is the easy part, like MM_openBrWindow().)
2)    The (new) window (focus) needs to always stay on top of the parent window until it is closed. (The new window will always be smaller than the parent window that spawned it and will always float in front of it.)
3)    If other (different) URLs are called, they replace the contents of the new window. (There shouldn’t be multiple windows floating above the main, parent window.)
I don’t like having to take this kind of control of the browser away from the user, but this content is part of a e-Learning course and needs to restrict the user while they are in the lesson.
If anyone has any pointers to tutorials or have already worked with this type of script, I'd like to hear from you. I have had some success doing this using a standard HTML page using separate functions, but combining the functionality in a single script has eluded me.
Thank you for your time,
TPK

Answer 1

Thank you David,
This is very close to what I need. When I test this on a standard HTML page it works flawlessly. It is an excellent bit of work.
When I try in integrate it into a Captivate 3 project using a "click box behavior" to call the JavaScript, it runs into a little trouble. The main part of the script works just fine: It is the “return document.MM_returnValue” piece that Captivate has problems.
For example:
When I use the JavaScript in a standard HTML page the URL string looks like this:
<a href="http://www.mywebsite.com" title="MyTest Window" onclick="dpSmartLink(this.href,'newWin',800,600,'z:z','sc');return document.MM_returnValue">Test link</a>
In Captivate I have to structure the call a little different. I can't use the href= piece, so I that part into the first parameter.
My Steps:
I embed the actual function in the HTML page used as a shell for the swf file.
In the Captivate Project file, on the slide where I want to call this function, I:
Create a click box.
For action I select “JavaScript”. (When the user clicks the "click box", execute javascript.)
The script call is written like this:
javascript:dpSmartLink('http://www.mywebsite.com','newWin',800,600,'z:z','sc');return document.MM_returnValue;
What I get is a script error that refers to:
Error: ‘return’ statement outside of function
Code: 0
I seem to be missing a means to close the cunction so that the script appears to be one iten rather than two separate items. (I'll be 'fiddling' with it to see if I am missing something simple and am just not seeing it.)
I realize that this script was not created with Captivate in mind, and that Captivate imposes rather severe restrictions on what can be called using Javascript.
Do you have any ideas as to how I might script the return statement so that it is within the parentheses given what I have described (above)?
On another note, I think this will be a very nice addition to LMS courseware that I develop using standard HTML and Javascript. Thank you again for this fine script.
TPK