截取地址栏指定的参数

// var productID = QueryString(url, "id"); 截取地址栏指定的参数
function QueryString(value, fieldName) {
var urlString = value;
if (urlString != null) {
var typeQu = fieldName + "=";
var urlEnd = urlString.indexOf(typeQu);
if (urlEnd != -1) {
var paramsUrl = urlString.substring(urlEnd + typeQu.length);
var isEnd = paramsUrl.indexOf('&');
if (isEnd != -1) {
return paramsUrl.substring(0, isEnd);
}
else {
return paramsUrl;
}
}
else {
return null;
}
}
else {
return null;
}
}