function chglang(lang) { //v3.0
	var path = window.location.href;
	var org_part;
	var org_ind_part;
	var des_part;
	if(path.indexOf('/english/') != -1){
		org_part = "/english/"; 
	}else if(path.indexOf('/tc_chi/') != -1){
		org_part = "/tc_chi/"; 
	}else if(path.indexOf('/sc_chi/') != -1){
		org_part = "/sc_chi/"; 
	}else if(path.indexOf('/japanese/') != -1){
		org_part = "/japanese/"; 
	}else if(path.indexOf('/index.php') != -1){
		org_part = "/index.php"; 
	}else if(path.indexOf('/jindex.php') != -1){
		org_part = "/jindex.php"; 
	}else if(path.indexOf('/scindex.php') != -1){
		org_part = "/scindex.php"; 
	}else if(path.indexOf('/tcindex.php') != -1){
		org_part = "/tcindex.php"; 
	}
	
	switch(lang){ 
		case 'english': 
			des_ind_part = "/index.php"; 
			des_part = "/english/";
			break;
		case 'tc_chi': 
			des_ind_part = "/tcindex.php"; 
			des_part = "/tc_chi/";
			break;
		case 'sc_chi': 
			des_ind_part = "/scindex.php"; 
			des_part = "/sc_chi/";
			break;
		case 'japanese': 
			des_ind_part = "/jindex.php"; 
			des_part = "/japanese/";
			break;
	}
 
	if(path.indexOf('index.php') != -1){
		tail = path.replace(org_part, des_ind_part);
	}else{
		tail = path.replace(org_part, des_part);
	}
  
  if(path.indexOf('.php')==-1){window.location.href+=des_ind_part.substring(1);}else{window.location.href=tail;}
}