isNS4 = (document.layers) ? true : false;
  isIE4 = (document.all && !document.getElementById) ? true : false;
  isIE5 = (document.all && document.getElementById) ? true : false;
  isNS6 = (!document.all && document.getElementById) ? true : false;

  function openpopup(popup,id) {
   var dwidth=370; var dheight=190;
   var leftpos = (self.screen.width / 2) - (dwidth / 2);
   var toppos = (self.screen.height / 2) - (dheight / 2);
   if (isIE5) window.showModalDialog('/inc/popup.'+popup+'.php?which='+id,'Send','dialogHeight:'+dheight+'px; dialogWidth:'+dwidth+'px; resizable:yes; status:no'); 
   if (isNS6) {
     window.open('/inc/popup.'+popup+'.php?which='+id,'Send','status=no,width='+dwidth+',height='+dheight+',left='+leftpos+',top='+toppos+''); 
	 return false;
  }
  }
  
  function setenable(frm) {
	for (i=0;i<=3;i++) {
	  if (frm.name!==frm.form.elements[i].name) frm.form.elements[i].disabled = true;
	}
	frm.disabled = false;
  }