multiple set of references at the ned of manuscript

Hi

I am using endnote for preparation of my manuscript for publication. I have created a library of the refernces and I have cited the references in the manuscript, but every time I open the endnote and the MS word file of the manuscript for doing some corrections or adding new references a new set of reference is added to the end of my manuscript, so some times I have 3 sets of the same reference list at the end. I dont know what to do to only have one reference set at the end?

thanks in advance

this is usually due to corrupt field codes, Follow FAQ 15 here, (which has a different problem, but the same solution). 

You might try (on a backup copy of the original document) to “unformat” the in-text citations/bibliography then reformat them. If using MS Word 2007 or 2010 go to the EndNote tab in the MS Word toolbar, click “Convert Citations and Bibliography” then click “Convert to Unformatted Citations”.  This will unformat the citations. Then click “Update Citations and Bibliography” to reformat them.

If you continue to have duplicate reference lists it may indicate a mis-setting in the output style.