function tabit(btn) { 
    var idname = new String(btn.id); 
    var s = idname.indexOf("_"); 
    var e = idname.lastIndexOf("_")+1; 
    var tabName = idname.substr(0, s); 
    var id = parseInt(idname.substr(e, 1)); 
    var oTab = btn.parentNode.getElementsByTagName('li'); 
    var k = 0, tabNumber = 0; 
    while (k < oTab.length) { 
        if (oTab.item(k).nodeName == 'LI') 
            tabNumber = tabNumber + 1; 
        k++; 
    } 
    for(i=0;i <tabNumber;i++){ 
            document.getElementById(tabName+"_div_"+i).style.display = "none"; 
            document.getElementById(tabName+"_btn_"+i).className = ""; 
    }; 
    document.getElementById(tabName+"_div_"+id).style.display = "block"; 
    btn.className = "curr"; 
}