function game_list(gameid) {
         var server_name = document.getElementById("server_name");
         var server_name_count = server_name.options.length;
         for (var i = 0; i < server_name_count; i++) {
            server_name.options.remove(1); //刪除選項
         }
	
         var field = document.getElementById("field");
	      if (field != null){
        	   var field_count = field.options.length;
        	   for (var i = 0; i < field_count; i++) {
            		field.options.remove(1); //刪除選項
         	}
        	   var span_field = document.getElementById("span_field");
        	   span_field.style.visibility = "visible";
	      }
        if (gameid == 12) {
        
            server_name.add(new Option("新東京校區_5", "19"));
        
            server_name.add(new Option("亂鬥伺服器_2", "47"));
        
            //server_name.add(new Option("千葉伺服器","9999"));
        
	    if (field != null){
            	field.add(new Option("第一分流", "1"));
            	field.add(new Option("第二分流", "2"));
            	field.add(new Option("第三分流", "3"));
	    }
        }
        if (gameid == 13) {
        
            server_name.add(new Option("泰麗亞", "23"));
        
            server_name.add(new Option("荷立帝", "29"));
        
            server_name.add(new Option("荷立帝", "31"));
                
	    if (field != null){
            	field.add(new Option("第一分流", "1"));
	    }
        }
        if (gameid == 15) {
                       
	    if (field != null){
            	span_field.style.visibility = "hidden";
	    }    
        }
        if (gameid == 20) {
        
            server_name.add(new Option("塞德斯", "44"));
        
            server_name.add(new Option("康希路斯", "45"));
         
	    if (field != null){
            	field.add(new Option("第一分流", "1"));
            	field.add(new Option("第二分流", "2"));
            	field.add(new Option("第三分流", "3"));
            	field.add(new Option("第四分流", "4"));
	    }  
        }
        if (gameid == 22) {
        
            server_name.add(new Option("第一伺服器", "35"));
         
	    if (field != null){
            	span_field.style.visibility = "hidden";
	    }  
        }
        if (gameid == 23) {
        
            server_name.add(new Option("羅蘭聖域", "40"));
         
	    if (field != null){
            	span_field.style.visibility = "hidden";
	    }  
        }
    }