Self made portal can not open reports in same frame

Question

i was making a self made portal using BusinessObjects Enterprise Java SDK, there is a html page showing the reports, the left frame is a tree, when clicking the item, it will show the report in the right frame.
  But the problem is when i click the second report in the tree, it will appear in the new  tab. i have tested  in chrome, ie, Firefox.
i  have a  function getting  the open document url which  is below :
  <%!
//return the open document url by Docid
String opendocUrl(int id, String token){
     return ( "http://huangli:8080/OpenDocument/opendoc/openDocument.jsp?iDocID=" +
               id + "&token=" + token);
I don't  understand why  it  works  well when i click the first report ,but not working if i click the second report !
thanks a million i am looking forward to your reply!

Answer 1

function clickOnLink(clickedId, target, windowName) {
    highlightObjLink(findObj(clickedId));
    if (isLinked(target)) {
        window.open(target,windowName);
this is the JavaScript code when i click the node .i have tested in IE,chrome ,FF. the target parameters is the frame name Windowsname is the URL of the report .i cannot see anything wrong .