function changeHomeProvince(f)
{
	var provinceIDList = f.elements["homeProvince"];
	var cityIDList = f.elements["homeCity"];

	var provinceSelected = provinceIDList.selectedIndex;
	var selectedProvinceID = provinceIDList[provinceSelected].value;

	for (i=cityIDList.length -1; i > 0; i--)
		cityIDList.options[i] = null;

	if (provinceSelected != 0)
	{

		var cityMap = provinceCityMap[selectedProvinceID];
		var tempNumItem = 1;
		for (i=0; i< cityMap.length; i++)
		{
			cityIDList.options[tempNumItem++] = new Option(cityMap[i][1], cityMap[i][0]);
		}
	}
}


/*
省市县商圈下拉框选择判断函数
zhanzhijian 2007-03-25

*/
function getSelect(obj_Op,id){
		if(typeof(obj_Op)=="undefined")
			return ;
			
		var obj = obj_Op.options;
		if(obj.length=="undefined")
			 return ;			 
		
		var len=obj.length;
		var id;
		var name;
		for(var i=0;i<len;i++){
	    	if(obj_Op.options[i].value==id){
		 		obj_Op.options[i].selected="selected";;
	   		}
		}
}

function clearOption(obj){
	if(typeof(obj)!="undefined"){
		if(obj.length>1){
			for(j=obj.length-1; j>0; j--)
				obj.options[j] = null;
		}
	}
}

function changeProvince(f){
	var provinceIDList = f.elements["province"];
	var cityIDList = f.elements["city"];
	var countyIDList = f.elements["county"];
	
	var provinceSelected = provinceIDList.selectedIndex;
	var selectedProvinceID = provinceIDList[provinceSelected].value;	
	//要判断县级下拉框是否存在，如果存在就清空
	if(typeof(f.elements["county"])!="undefined")
		clearOption(countyIDList);
	//选了省下拉框后，如果有市级下拉框的话，则进行判断	
	if (typeof(f.elements["city"])!="undefined"){
		clearOption(cityIDList);	
		if(provinceSelected != 0){
			var cityMap = provinceCityMap[selectedProvinceID];
			var tempNumItem = 1;
			for (i=0; i< cityMap.length; i++)
				cityIDList.options[tempNumItem++] = new Option(cityMap[i][1], cityMap[i][0]);
		}
	}
}

function changeCity(f){
	var cityIDList = f.elements["city"];
	var countyIDList = f.elements["county"];
	
	var citySelected = cityIDList.selectedIndex;
	var selectedCityID = cityIDList[citySelected].value;
	
	//要判断县级下拉框是否存在
	if(typeof(f.elements["county"])!="undefined"){		
		//清空县级下拉框
		clearOption(countyIDList);
		if (citySelected != 0)
		{
			//alert(selectedCityID);
			if(typeof(countyCityMap[selectedCityID])!="undefined"){
				var cityMap = countyCityMap[selectedCityID];
				var tempNumItem = 1;
				for (i=0; i< cityMap.length; i++)
				{
					countyIDList.options[tempNumItem++] = new Option(cityMap[i][1], cityMap[i][0]);
				}	
			}				
		}
	}
	changeDistrict(f,selectedCityID);
}


function changeDistrict(f,cityID){
	//首先判断商圈下拉框控件是否存在，如果不存在就返回
	if(typeof(f.elements["businessDistrict"])=="undefined")
		return;
	var districtList = f.elements["businessDistrict"];	
	//接着判断SowntownList+cityID是否定义，因为有些城市可能没有商业区
	if(eval("typeof(" + "SowntownList"   +   cityID   +   ")")=='undefined'){
		clearOption(districtList);
		return;
	}	
	else{	
		var itemArray = eval("SowntownList"+cityID);	//得到SowntownList0101		
		clearOption(districtList);			
		if(	itemArray.length>0){
			for(i=0;i<itemArray.length;i++)
			{
				districtList.options[i] = new Option(itemArray[i][1], itemArray[i][0]);
			}
		}
	}
}


//当切换城市时，导航栏的所有地区变成市区和所有商圈
function changeTopCityAndDistrict(cityId){
	var cityAndDistrictList = document.forms[0].elements["top_district"];
	//alert(cityAndDistrictList.length);
	clearOption(cityAndDistrictList);
	if (cityId != 0){
			if(typeof(countyCityMap[cityId])!="undefined"){
				var cityMap = countyCityMap[cityId];
				var tempNumItem = 1;
				for (i=0; i< cityMap.length; i++)
				{
					cityAndDistrictList.options[tempNumItem++] = new Option(cityMap[i][1], "county:"+cityMap[i][0]+":"+cityMap[i][1]);
				}
				//alert(cityId);			
				if(eval("typeof(" + "SowntownList"   +   cityId   +   ")")=='undefined'){
					return;
				}
				var itemArray = eval("SowntownList"+cityId);	//得到SowntownList0101
				//alert(itemArray.length);	
				//alert("tempNumItem="+tempNumItem);//19
				//alert("cityAndDistrictList.length="+cityAndDistrictList.length);//19
				if(	itemArray.length>0){
					//alert("a");
					for(i=tempNumItem;i<itemArray.length+tempNumItem;i++){
						//alert("b="+i);//从19开始
						cityAndDistrictList.options[i] = new Option(itemArray[i-tempNumItem][1], "district:"+itemArray[i-tempNumItem][0]+":"+itemArray[i-tempNumItem][1]);
					}
				}	
			}				
		}
	//}
}


/*住宿搜索页面，当切换城市时，改变商业区和行政区的下拉框
   zhanzhijian 2007-05-01
*/
function changeBusinessDistrictOrCountyList(cityId,type){
	//alert(typeof(document.forms["inNation"]));
	if(typeof(document.forms["inNation"])=="undefined")
		return ;
	var cityAndDistrictList = document.forms["inNation"].elements["districtID"];
	if(typeof(cityAndDistrictList)=="undefined")
		return;
	//alert(cityAndDistrictList.length);
	clearOption(cityAndDistrictList);
	//alert("cityId="+cityId+",type="+type);
	if (cityId != 0){
			if(typeof(countyCityMap[cityId])!="undefined"){			
				if(type=="county"){
					var cityMap = countyCityMap[cityId];
					var tempNumItem = 1;
					cityAndDistrictList.options[0] = new Option("--行政区--", "");
					for (i=0; i< cityMap.length; i++)
					{
						cityAndDistrictList.options[tempNumItem++] = new Option(cityMap[i][1], cityMap[i][0]);
					}
					//alert(cityId);			
					if(eval("typeof(" + "SowntownList"   +   cityId   +   ")")=='undefined'){
						return;
					}
				}else if(type=="district"){				
					var itemArray = eval("SowntownList"+cityId);	//得到SowntownList0101
					//alert(itemArray.length);	
					//alert("tempNumItem="+tempNumItem);//19
					//alert("cityAndDistrictList.length="+cityAndDistrictList.length);//19
					if(	itemArray.length>0){
						//alert("a");
						for(i=0;i<itemArray.length;i++){
							//alert("b="+i);//从19开始
							cityAndDistrictList.options[i] = new Option(itemArray[i][1], itemArray[i][0]);
						}
					}	
				}
			}				
		}
	//}
}


/*住宿搜索页面，当切换城市时，改变商业区和行政区的下拉框
   wangzhongyuan 2007-05-02
   这个方法与上面那个方法类似，不过可以动态传入form名字，不直接修改上面那个，是为了预防在一些未知地方出错
*/
function changeDistrictOrCountyListByForm(objform,cityId,type){
	//alert(typeof(objform));
	if(typeof(objform)!="object")
	{	
		alert("传入的form不正确");
		return ;
	}
	var cityAndDistrictList = objform.elements["districtID"];
	
	//alert(cityAndDistrictList.length);
	clearOption(cityAndDistrictList);
	if (cityId != 0){
			if(typeof(countyCityMap[cityId])!="undefined"){			
				if(type=="county"){
					var cityMap = countyCityMap[cityId];
					var tempNumItem = 1;
					cityAndDistrictList.options[0] = new Option("--行政区--", "");
					for (i=0; i< cityMap.length; i++)
					{
						cityAndDistrictList.options[tempNumItem++] = new Option(cityMap[i][1], cityMap[i][0]);
					}
					//alert(cityId);			
					if(eval("typeof(" + "SowntownList"   +   cityId   +   ")")=='undefined'){
						return;
					}
				}else if(type=="district"){				
					var itemArray = eval("SowntownList"+cityId);	//得到SowntownList0101
					//alert(itemArray.length);	
					//alert("tempNumItem="+tempNumItem);//19
					//alert("cityAndDistrictList.length="+cityAndDistrictList.length);//19
					if(	itemArray.length>0){
						//alert("a");
						for(i=0;i<itemArray.length;i++){
							//alert("b="+i);//从19开始
							cityAndDistrictList.options[i] = new Option(itemArray[i][1], itemArray[i][0]);
						}
					}	
				}
			}				
		}
	//}
}