add: var target = (isargobject) ? tagid : getElementById(tagid); 
context: function toggleVisibility(tagid, displaystyle, isargobject){  try {    var wasvis = isVisible(tagid, displaystyle, isargobject);    setVisible(tagid, !wasvis, displaystyle, isargobject);    target.style.zIndex = (wasvis) ? 0 : 1;    return wasvis;  } catch (ex) {}}
meta: 4474	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/4474/138d06fd8010cdfe5f84698ca680b5c1276211f0/display.js/buggy/htdocs/display.js