function getElementsByClass(className) {
  var all = document.all ? document.all : document.getElementsByTagName('*');
  var elements = new Array();

  for (var e = 0; e < all.length; e++)
    if (all[e].className == className && all[e].id.indexOf('nb') == -1)
      elements[elements.length] = all[e];

  return elements;
} 

function showHide(divNo) {

	var tip = "tip" + divNo;
	var tab = "tab" + divNo;
    
    document.getElementById("tip1").className = "tab_bg";
    document.getElementById("tip2").className = "tab_bg";
    document.getElementById("tip3").className = "tab_bg";
    document.getElementById("tip4").className = "tab_bg";
        
    document.getElementById("tab1").className = "tab_hide";
    document.getElementById("tab2").className = "tab_hide";
    document.getElementById("tab3").className = "tab_hide";
    document.getElementById("tab4").className = "tab_hide";
	
	document.getElementById(tip).className = "tab_selected";
	document.getElementById(tab).className = "tab_view";
}