function getUrlVal(para) {
		var search = location.search; //页面URL的查询部分字符串  
		var arrPara = new Array(); //参数数组。数组单项为包含参数名和参数值的字符串，如“para=value”  
		var arrVal = new Array(); //参数值数组。用于存储查找到的参数值  

		if (search != "") {
			var index = 0;
			search = search.substr(1); //去除开头的“?”  
			arrPara = search.split("&");

			for (i in arrPara) {
				var paraPre = para + "="; //参数前缀。即参数名+“=”，如“para=”  
				if (arrPara[i].indexOf(paraPre) == 0
						&& paraPre.length < arrPara[i].length) {
					arrVal[index] = decodeURI(arrPara[i].substr(paraPre.length)); //顺带URI解码避免出现乱码  
					index++;
				}
			}
		}

		if (arrVal.length == 1) {
			return arrVal[0];
		} else if (arrVal.length == 0) {
			return null;
		} else {
			return arrVal;
		}
	}