一些常用的JS (JONEAjax) 获取dom 对象，ajax操作，读写cookie

/*******************************************************************************
* JONEAjax 获取dom 对象，ajax操作，读写cookie
* @author Roddy <minguiluo@gmail.com>
* @site http://www.cnblogs.com/luomingui/
* @version 1.0.0
*******************************************************************************/
var LF = {};
LF.version = '1.0.0';
//全局函数
function $(objName) {
    return document.getElementById(objName);
}
function $name(objName) {
        return document.getElementsByName(objName);
}
function $tag(objName) {
        return document.getElementsByTagName(objName);
}

//广告swf　 flashWrite('SW/2009/HomeGroBuy.swf','950','70','navigation', '##ffffff', 'menuNum=0', 'transparent');
function flashWrite(url,w,h,id,bg,vars,win){
 var flashStr=
 "<div align=\"center\"><object classid='clsid:d27cdb6e-ae6d-11cf-96b8-444553540000' codebase='http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=8,0,0,0' width='"+w+"' height='"+h+"' id='"+id+"' align='middle'>"+
 "<param name='allowScriptAccess' value='always' />"+
 "<param name='movie' value='"+url+"' />"+
 "<param name='FlashVars' value='"+vars+"' />"+
 "<param name='wmode' value='"+win+"' />"+
 "<param name='menu' value='false' />"+
 "<param name='quality' value='high' />"+
 "<param name='bgcolor' value='"+bg+"' />"+
 "<embed src='"+url+"' FlashVars='"+vars+"' wmode='"+win+"' menu='false' quality='high' bgcolor='"+bg+"' width='"+w+"' height='"+h+"' name='"+id+"' align='middle' allowScriptAccess='always' type='application/x-shockwave-flash' pluginspage='http://www.macromedia.com/go/getflashplayer' />"+
 "</object></div>";
 document.write(flashStr);
}
//广告图片  imgWrite('images/pic04.jpg', '780', '90', 'http://www.lfang.com/wzzt/2009/lgzt/');
function imgWrite(url,w,h,linkUrl){
 var flashStr= "";
 if (linkUrl=="")
    flashStr="<img src=\""+url+"\" border=\"0\" width=\""+w+"\" height=\""+h+"\"/>";
 else
    flashStr="<a href=\""+linkUrl+"\">"+"<img src=\""+url+"\" border=\"0\" width=\""+w+"\" height=\""+h+"\"/>"+"</a>";
 document.write(flashStr);
}

//AJAX操作
LF.ajax={
     getXmlhttp : function() {
        var http_request;
     if(window.XMLHttpRequest) {
      http_request = new XMLHttpRequest();
      if (http_request.overrideMimeType) {
       http_request.overrideMimeType("text/xml");
      }
     }
     else if (window.ActiveXObject) {
      try {
       http_request = new ActiveXObject("Msxml2.XMLHTTP");
      } catch (e) {
       try {
        http_request = new ActiveXObject("Microsoft.XMLHTTP");
       } catch (e) {}
      }
     }
     if (!http_request) {
      window.alert("can't create XMLHttpRequest object.");
      return null;
     }
     return http_request;
    },
    loadAJAXTab : function (url){// 一般是DIV
      try {
       var xhttp=LF.ajax.getXmlhttp(); 
       xhttp.open("GET",url,false);
       xhttp.send(null); 
          if (xhttp.readyState == 0)return "0初始化中......";
          if (xhttp.readyState == 1)return "1初始化中......";
          if (xhttp.readyState == 2)return "2初始化中......";
          if (xhttp.readyState == 3)return "3初始化中......";
       if(xhttp.readyState == 4 && (xhttp.status==200)){  
         var resText=xhttp.responseText;
         if (resText!="")return resText;
       }
   
   }catch (e) {
     return e;
   }
    },
    dataSubmit:function(url,urlParameter,method){ //ajax post提交数据
      try{
          if(method==""){method="POST";}
          var xhttp=LF.ajax.getXmlhttp();
          xhttp.open(method, url+urlParameter, false);
          xhttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
          xhttp.send(null);
          if (xhttp.readyState == 0)return "0初始化中......";
          if (xhttp.readyState == 1)return "1初始化中......";
          if (xhttp.readyState == 2)return "2初始化中......";
          if (xhttp.readyState == 3)return "3初始化中......";
          if (xhttp.readyState == 4 && xhttp.status == 200)return xhttp.responseText;   
        }catch(e){
           return e;
       }
    }
};
//工具
LF.util = {
    setCookie:function (name,value){//写cookies
        var Days = 30;
        var exp = new Date();
        exp.setTime(exp.getTime() + Days*24*60*60*1000);
        document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
    },
    getCookie:function (name){//读取cookies
        var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
        if(arr=document.cookie.match(reg)) return unescape(arr[2]);
        else return null;
    },
    delCookie:function (name){//删除cookies
        var exp = new Date();
        exp.setTime(exp.getTime() - 1);
        var cval=getCookie(name);
        if(cval!=null) document.cookie= name + "="+cval+";expires="+exp.toGMTString();
    },
    escape:function (html) {//过滤html
        html = html.replace(/&/g, "&amp;");
        html = html.replace(/</g, "&lt;");
        html = html.replace(/>/g, "&gt;");
        html = html.replace(/\xA0/g, "&nbsp;");
        html = html.replace(/\x20/g, " ");
        return html;
    }

};