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<DIV>Christian,</DIV>
<DIV>This is a link to microsoft's explanation of set_union()...it has sample code.</DIV>
<DIV> </DIV>
<DIV><A href="http://msdn2.microsoft.com/en-us/library/a20tb7e2.aspx">http://msdn2.microsoft.com/en-us/library/a20tb7e2.aspx</A></DIV>
<DIV> </DIV>
<DIV>There are also set_intersection and set_difference()</DIV>
<DIV> </DIV>
<DIV>HTH,</DIV>
<DIV>Philip</DIV></body></html>