XML manipulation

Ok here is what I've got so far...it's pretty basic and what i want to accomplish shouldnt be that hard but for some reason i just cant figure it out.
http://www.hybridart.com/test/flash/

When you click main nav it should show items only from that category in the 2nd nav box. but problem is when you click one it displays them in the number of the array on 2nd menu and then when you change main categories it just keeps adding to them until all items in array are displayed. can someone help me have them list correctly? these are being pulled from an xml file and all the links are being generated dynamically.

here are the source files
http://www.hybridart.com/test/flash/xml_dynamic_button_test.zip

here is actionscript

var numCats:Number = xmlProject.category.catname.length;
var numProjects:Number = xmlProject.project.length;
var ProjectArray:Array = new Array();
var CatArray:Array = new Array();

for (var c:Number = 0; c <numCats; c++) {
      CatArray[c] = xmlProject.category.catname[c].getValue();
};
//loop to display all categories in category node
for(var j:Number = 0; j < numCats; j++) {
      //create button instances
      var mc = copyButton.duplicateMovieClip("copy"+j,j+10);
      //position button instances
      mc._x = 4.5;
      mc._y = 67+(j*17);
      //update text on button instances with catname node
      mc.linktitle.htmlText = xmlProject.category.catname[j].getValue();
      //set var to pass into onreleaseFunction
      mc.i=j;
      mc.onRelease = function() {
            //trace(xmlProject.category.catname[this.i].getValue());
            currCat = xmlProject.category.catname[this.i].getValue();
            _root.gotoAndPlay(3);
      }
      mc.onRollOver = function() {
            this.gotoAndPlay("on");
            this.linktitle.textColor = 0xFFFFFF;
      }
      mc.onRollOut = function() {
            this.gotoAndPlay("off");
            this.linktitle.textColor = 0x999999;
      }
}

//Display all Projects by Title Node
for (var i:Number = 0; i < numProjects; i++) {
      //show only projects that match clicked category
      if (xmlProject.project[i].category.getValue() == currCat){
            for (var pa:Number = 0; pa < numProjects; pa++) {
                  ProjectArray[pa] = xmlProject.project[pa].title.getValue();
                  trace(i);
            }
            //ProjectArray.sort();
      //create duplicated button instances
      var ProjLinksMC = copyButton.duplicateMovieClip("projlinks"+i,i+30);
      //position button instances
      ProjLinksMC._x = 130;
      ProjLinksMC._y = 67+(i*17);
      //update text on button instances with title node
      ProjLinksMC.linktitle.htmlText = ProjectArray[i];
      //ProjLinksMC.linktitle.htmlText = xmlProject.project[i].title.getValue();
      //set var to pass inside onRelease function
      ProjLinksMC.j=i;
      //onRelease function
      ProjLinksMC.onRelease = function() {
            screenshot.loadMovie(xmlProject.project[this.j].screenshot.getValue());
            projText.title.htmlText = xmlProject.project[this.j].projecttitle.getValue();
            projText.comment.htmlText = xmlProject.project[this.j].comments.getValue();
      }
      ProjLinksMC.onRollOver = function() {
            this.gotoAndPlay("on");
            this.linktitle.textColor = 0xFFFFFF;
      }
      ProjLinksMC.onRollOut = function() {
            this.gotoAndPlay("off");
            this.linktitle.textColor = 0x999999;
      }
      }
}

stop();