var d = document;

  function $(id, f){
   	return eval('d.getElementById(id)' + (f? '.style' : ''));
  }
  
  function show_hide(id){
    obj = document.getElementById(id);
    obj.style.display=(obj.style.display=='')?'none':'';
  }
  
  function chClassName(obj, newCl){
    obj.className=(obj.className=='')?newCl:'';
  }
  
  function chImg(url){
    big = document.getElementById('bigImg');
    big.src = url; 
  }
  
  
  function chTab (obj, selTabName){
    selTab = $(selTabName);
    selTabCont = $(selTabName + "Cont");
    objCont = $(obj.id + "Cont");
    
    
    selTabCont.style.display = "none";
    selTab.className = "";

    objCont.style.display = "block";
    obj.className = "sel";
    
  }