function toggle(tgt) {
 var divT = document.all['div_'+tgt];
 var imgT = document.all['img_'+tgt];
 var divTs = divT.style.display;
 var jump = 0;
 if (divTs == 'none') {
   divT.style.display  = 'block';
   imgT.src='../img/collapse.gif';
   var jump = 1;
 }
 if (jump == 0) {
   divT.style.display  = 'none';
   imgT.src='../img/expand.gif';
 }
 return true;
}