function changeTab(tab){var container=$("tabs");var children=$(container).childElements();container.className="tabs";var tabIndex=parseInt(tab.id.split("_")[1])-1;for(var i=0;i<children.length;i++){var page=$("page_"+i);if(page!=null){if(i==tabIndex){container.className+=" "+tab.id;page.style.display="block"}else{page.style.display="none"}}}};