var selTab=1;
tabChange = function(a) {
	var oldtab = document.getElementById("tab"+selTab); 
	if (oldtab) {
	    oldtab.style.display = "none";
      }
	var newtab = document.getElementById("tab"+a); 
      newtab.style.display = "block";
	

	var oldlink = document.getElementById("link"+selTab); 
      if (oldlink) {
		oldlink.setAttribute("class", ""); 
		oldlink.setAttribute("className", ""); 
	}

      var newlink = document.getElementById("link"+a); 
	newlink.setAttribute("class", "active"); 
	newlink.setAttribute("className", "active"); 
      
      selTab = a;
}