function toggle(image,list){
      var listElementStyle=document.getElementById(list).style;
      if (listElementStyle.display=="none"){
        listElementStyle.display="block";
        document.getElementById(image).src="images/txticon.gif";
        document.getElementById(image).alt="Close list";
      }else{
        listElementStyle.display="none";
        document.getElementById(image).src="images/txticon.gif";
        document.getElementById(image).alt="Open list";
      }
    }