/*********js获取对象***********/
function getObject(objectId) {
    if(document.getElementById && document.getElementById(objectId)) {
	// W3C DOM
	return document.getElementById(objectId);
    } else if (document.all && document.all(objectId)) {
	// MSIE 4 DOM
	return document.all(objectId);
    } else if (document.layers && document.layers[objectId]) {
	// NN 4 DOM.. note: this won't find nested layers
	return document.layers[objectId];
    } else {
	return false;
    }
}
/********验证搜索框架**********/
function checksearch(myform){
if(myform.keyword.value=='请输入你想查找的内容'){
 alert("请输入你想查找的内容");
 return false;
}else{
 return true;
}
}
/******搜索选项卡***********/
function change_tab(id,n,class_act,class_nor,tab_id){
	var tab='tab_'+tab_id;
	var tabc=tab+"_"+id;
	for(var i=1;i<=n;i++){
		var tab1=tab+"_"+i;
		getObject(tab1).className=class_nor;    
	}
	getObject(tabc).className=class_act;
	if(tab_id==1){
		if(id=='1'){
			document.getElementById('keyword').value="请输入你想查找的内容";
			document.getElementById('main_serach').action="/sell_list.php?";
		}else if(id=="2"){
			document.getElementById('keyword').value="请输入你想查找的内容";
			document.getElementById('main_serach').action="/clist.php?";
		}else if(id=="3"){
			document.getElementById('keyword').value="请输入你想查找的内容";
			document.getElementById('main_serach').action="/do/search.php";
		}else{
			document.getElementById('keyword').value="请输入你想查找的内容";
			document.getElementById('main_serach').action="/buy_list.php?";
		}
  }				
	
}

function OnEnter( field )
{ 
	if( field.value == field.defaultValue ) { 
	field.value = ""; 
	} 
}
function OnExit( field ) 
{ 
	if( field.value == "" ) { 
	field.value = field.defaultValue; 
	} 
}

function CheckLogin(){
//接收表单的URL地址
	var url = "http://www.b2cf.cn/do/hack0813.php";
	var postStr = "id"+123;
	
	//实例化Ajax
	var ajax = false;
	  //开始初始化XMLHttpRequest对象
	if(window.XMLHttpRequest) { //Mozilla 浏览器yy
		  ajax = new XMLHttpRequest();
		  if (ajax.overrideMimeType) {//设置MiME类别
				  ajax.overrideMimeType("text/xml");
		  }
	}else if (window.ActiveXObject) { // IE浏览器
		  try {
				  ajax = new ActiveXObject("Msxml2.XMLHTTP");
		  } catch (e) {
				  try {
						  ajax = new ActiveXObject("Microsoft.XMLHTTP");
				  } catch (e) {}
		  }
	}
	if (!ajax) { // 异常，创建对象实例失败
		  window.alert("不能创建XMLHttpRequest对象实例.");
		  return false;
	}

	//通过Post方式打开连接
	ajax.open("POST", url, true); 

	//定义传输的文件HTTP头信息
	ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); 
	//发送POST数据
	ajax.send(postStr);
	//获取执行状态
	ajax.onreadystatechange = function() { 

		//如果执行状态成功，那么就把返回信息写到指定的层里
		if (ajax.readyState == 4 && ajax.status == 200) { 
			  getObject("Login").innerHTML = ajax.responseText;
		} 
	} 
}