Check replicant children for duplicates?

System

hello all...im trying to parse thru a list of a few hundred replicant nodes and alert the user on duplicates, and what the duplicates are.

i.e., the template is used for entering courses, and the users often enters the same course ID (which has to be unique) again instead of updating an existing course.

I am able to get the children course values, but i cant get the array or string checkers ive googled to work. any help would be greatly appreciated, thanks!

here are some of the examples ive been trying to use... http://stackoverflow.com/questions/840781/easiest-way-to-find-duplicate-values-in-a-javascript-array

IN THE DCT

[HTML]

arg1
[/HTML]

FORMAPI

function checkForDuplicateCourses(item) {

 var csv = "";
 var children = IWDatacapture.getItem("/Root/Courses").getChildren();

 for (var i = 0; i < children.length; i++) 
  {
   var child = children;
   courseID = IWDatacapture.getItem(child.getName() + "/" + "CourseID").getValue();
   csv = csv + courseID + ",";
  }
 alert(csv);

 alert("Done!");
}