var currentPanel;
function showPanel(panelNum) {
      //hide visible panel, show selected panel, 
      //set tab
      if (currentPanel != null) {
         hidePanel();
      }
      document.getElementById('tab'+panelNum).style.visibility = 'visible';
      document.getElementById('tab'+panelNum).style.position = 'relative';
         currentPanel = panelNum;
         document.getElementById('tabLink'+panelNum).className= 'selected';
   }
   
   function hidePanel() {
      //hide visible panel, unhilite tab
      document.getElementById
        ('tab'+currentPanel).style.visibility = 
         'hidden';
      document.getElementById
        ('tab'+currentPanel).style.position = 
        'absolute';
   }
   
   function setState(setSelected, setUnselected, setUnselected2) {
   		setEle = document.getElementById('tabLink' + setSelected);
   		removeEle = document.getElementById('tabLink' + setUnselected);
   		removeEle2 = document.getElementById('tabLink' + setUnselected2);
   		
   	    addClass(setEle, 'selected');
   	    removeClass(removeEle, 'selected');
   	    removeClass(removeEle2, 'selected');
   }
   
 function hasClass(ele,cls) {
	return ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));
}

function addClass(ele,cls) {
	if (!this.hasClass(ele,cls)) ele.className += " "+cls;
}
function removeClass(ele,cls) {
	if (hasClass(ele,cls)) {
		var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
		ele.className=ele.className.replace(reg,' ');
	}
}