<!-- This piece of JavaScript should be placed in the <HEAD> section of -->
<!-- the html page.                                                     -->

<SCRIPT LANGUAGE="JavaScript">
var table='c1';
function combo(table) {

  if (table=='c1') {
    if (document.all.c1.style.visibility=="hidden") {
        document.all.c1.style.visibility="visible";
    }
    else {document.all.c1.style.visibility="hidden";}
  }

  if (table=='c2') {
    if (document.all.c2.style.visibility=="hidden") {
        document.all.c2.style.visibility="visible";
    }
    else {document.all.c2.style.visibility="hidden";}
  }

  if (table=='c3') {
    if (document.all.c3.style.visibility=="hidden") {
        document.all.c3.style.visibility="visible";
    }
    else {document.all.c3.style.visibility="hidden";}
  }

}
</SCRIPT>