function changeTab(n){
    var len=4;
    for(i=1;i<=len;i++){
		if(i ==n){
			document.getElementById("tab_"+i).style.display = "block";
			document.getElementById("tab_head_"+i).className = "isactive" + i;
		}else{
			document.getElementById("tab_"+i).style.display = "none";
			document.getElementById("tab_head_"+i).className = "noactive" + i;
		}
    }
}

function changeTab1(n,len){
    for(i=1;i<=len;i++){
		if(i ==n){
			document.getElementById("tab_"+i).style.display = "block";
			document.getElementById("tab_head_"+i).className = "isactive" + 1;
		}else{
			document.getElementById("tab_"+i).style.display = "none";
			document.getElementById("tab_head_"+i).className = "noactive" + 1;
		}
    }
}

var timeout; 
function delayChangeTab(m,n){
    timeout = setTimeout("changeTab("+m+")",n);
}

function cancelChangeTab(){
    clearTimeout(timeout);
}