/**
 * Define the getElementById() method 
 * to eliminate some cross browser problems
 */
if( ! document.getElementById){
  document.getElementById = function(element_id) {
    // This method returns the element corresponding to the id
    if (document.all) {
      return document.all[element_id];
    }
    else if (document.layers) {
      return document.layers[element_id];
    } else {
      return undefined;
    }
  }
}

var currentTabId = '';

/**
 * handles a tab click
 * @author seang
 */
function tabClick(tabId){
	if(currentTabId){
		document.getElementById(currentTabId).className = 'tab';
		document.getElementById(currentTabId + 'Content').style.display = 'none';
	}
	document.getElementById(tabId).className = 'tabOn';
	currentTabId = tabId;
	document.getElementById(tabId + 'Content').style.display = '';
}