diff --git a/AuthorizationHttpModule.cs b/AuthorizationHttpModule.cs
index 29f1af0..2db763a 100644
--- a/AuthorizationHttpModule.cs
+++ b/AuthorizationHttpModule.cs
@@ -8,7 +8,7 @@
 using System.Web.UI;
 
 /// <summary>
-/// Verify authorization on requests to AJAX WebServices or Pages.
+/// Verify authorization on call to WebMethods or Pages with the attribute: &lt;RequiresAuthentication&gt; (VB) | [RequiresAuthentication] (C#).
 /// </summary>
 [AttributeUsage(AttributeTargets.Method | AttributeTargets.Class)]
 public class RequiresAuthenticationAttribute : Attribute { }
@@ -33,7 +33,7 @@ public void Dispose() {
     }
 
     /// <summary>
-    /// Authorize request.
+    /// A request has hit IIS. This events handles authorization for the given request.
     /// </summary>
     /// <param name="sender">Sender Parameter</param>
     /// <param name="e">EventArgs Parameter</param>
@@ -43,8 +43,10 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
         var request = context.Request;
         var requestUrl = context.Request.Url.ToString();
 
-            if (context.Handler is Page page) {
+        //The request is for a Page Class:
+        if (context.Handler is Page page) {
             var pageType = page.GetType();
+            //Check if the MasterPage requires authentication:
             if (!requestUrl.Contains(".axd?")) {
                 var masterPagePath = GetMasterPagePathFromMarkup(page.AppRelativeVirtualPath);
                 if (!string.IsNullOrEmpty(masterPagePath)) {
@@ -58,6 +60,7 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
                 }
             }
 
+            //Check if the Page requires authentication:
             if (pageType.GetCustomAttribute<RequiresAuthenticationAttribute>() != null) {
                 if (!request.IsAuthenticated || request.Cookies?[FormsAuthentication.FormsCookieName] == null) {
                     DenyAccess(context);
@@ -65,6 +68,7 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
                 }
             }
 
+            //The request is for a WebMethod inside a Page Class:
             if (request.HttpMethod == "POST") {
                 var methodName = GetWebMethodNameFromRequest(request);
                 if (!string.IsNullOrEmpty(methodName)) {
@@ -76,10 +80,10 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
                     }
                 }
             }
+        };
 
-        } else if (requestUrl.Contains(".asmx/")) {
-            //Prøvd å hente Type via Handler._privateSomething
-
+        //The request is for a WebService Class:
+        if (!(context.Handler is Page) & requestUrl.Contains(".asmx/")) {
             var segments = requestUrl.Split(new[] { ".asmx/" }, StringSplitOptions.RemoveEmptyEntries);
             if (segments.Length > 1) {
                 string methodName = segments[1]; // Extract the part after .asmx/ as the method name
@@ -91,15 +95,28 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
                     dynamic _handler = context.CurrentHandler;
                     dynamic handlerWrapper = context.Handler;
 
+                    // Retrieve original handler and its metadata
                     if (handlerWrapper != null) {
-                        // Retrieve original handler and its metadata
                         var originalHandlerField = handlerWrapper.GetType().GetField("_originalHandler", BindingFlags.NonPublic | BindingFlags.Instance);
                         var originalHandler = originalHandlerField?.GetValue(handlerWrapper) as dynamic;
 
                         if (originalHandler != null) {
+                            //Session Disabled WebMethod is Called:
                             var webServiceMethodDataField = originalHandler.GetType().GetField("_webServiceMethodData", BindingFlags.NonPublic | BindingFlags.Instance);
                             var webServiceMethodData = webServiceMethodDataField?.GetValue(originalHandler) as dynamic;
 
+                            //If the WebService Method has SessionEnabled=True the RestHandlerWithSession is used, instead of RestHandler class.
+                            //RestHandlerWithSession is an empty class that inherits both the base RestHandler class and IRequireSessionState for session accsess
+                            //Because of this we need to get the class type in a different way, through the BaseType.
+                            //Since System.Web.Script.Services.RestHandlerWithSession is an internal class we also need to retive the type like so:
+                            Type _RestHandlerWithSessionType = Type.GetType("System.Web.Script.Services.RestHandlerWithSession, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35");
+
+                            //Session Enabled WebMethod is Called:
+                            if (_RestHandlerWithSessionType == originalHandler.GetType()) {
+                                webServiceMethodDataField = originalHandler.GetType().BaseType.GetField("_webServiceMethodData", BindingFlags.NonPublic | BindingFlags.Instance);
+                                webServiceMethodData = webServiceMethodDataField?.GetValue(originalHandler) as dynamic;
+                            };
+
                             if (webServiceMethodData != null) {
                                 var ownerField = webServiceMethodData.GetType().GetField("_owner", BindingFlags.NonPublic | BindingFlags.Instance);
                                 var owner = ownerField?.GetValue(webServiceMethodData) as dynamic;
@@ -112,10 +129,11 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
                                         var actualTypeField = typeData.GetType().GetField("_actualType", BindingFlags.NonPublic | BindingFlags.Instance);
                                         var actualType = actualTypeField?.GetValue(typeData) as dynamic;
 
+                                        //The WebMethod's Class Type is retrived, we can now check for Custom Attributes:
                                         var attributes = actualType.GetCustomAttributes(typeof(RequiresAuthenticationAttribute), true);
                                         bool requiresAuthentication = attributes.Length > 0;
 
-                                        // Check if authentication is required for the main class
+                                        //Check if authentication is required for the main class
                                         if (requiresAuthentication) {
                                             if (!request.IsAuthenticated || request.Cookies?[FormsAuthentication.FormsCookieName] == null) {
                                                 DenyAccess(context);
@@ -123,14 +141,13 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
                                             }
                                         }
 
-                                        // Check for authentication attribute on the requested method
+                                        //Check if authentication is required for the requested method
                                         if (!requiresAuthentication) {
                                             var methodInfo = actualType.GetMethod(methodName);
                                             if (methodInfo != null) {
                                                 var methodAttributes = methodInfo.GetCustomAttributes(typeof(RequiresAuthenticationAttribute), true);
                                                 bool methodRequiresAuthentication = methodAttributes.Length > 0;
 
-
                                                 if (methodRequiresAuthentication) {
                                                     if (!request.IsAuthenticated || request.Cookies?[FormsAuthentication.FormsCookieName] == null) {
                                                         DenyAccess(context);
@@ -140,7 +157,6 @@ private void OnPostAuthorizeRequest(object sender, EventArgs e) {
                                             }
                                         }
                                     }
-
                                 }
                             }
                         }
@@ -175,13 +191,21 @@ private string GetRelativeVirtualPath(string absolutePath) {
     }
 
     private string GetMasterPagePathFromMarkup(string virtualPath) {
+        string currentFolder = Path.GetDirectoryName(HttpContext.Current.Server.MapPath(virtualPath));
+
         string markup = File.ReadAllText(HttpContext.Current.Server.MapPath(virtualPath));
         using (StringReader reader = new StringReader(markup)) {
             string line;
             while ((line = reader.ReadLine()) != null) {
                 Match match = Regex.Match(line, "MasterPageFile\\s*=\\s*\"(.+?)\"");
                 if (match.Success) {
-                    return match.Groups[1].Value;
+                    string masterPagePath = match.Groups[1].Value;
+
+                    if (!VirtualPathUtility.IsAppRelative(masterPagePath)) {
+                        masterPagePath = VirtualPathUtility.Combine(virtualPath, masterPagePath);
+                    }
+
+                    return masterPagePath;
                 }
             }
         }
@@ -208,4 +232,4 @@ private static string GetWebMethodNameFromRequest(HttpRequest request) {
         var slashIndex = pathInfo.IndexOf('/');
         return slashIndex >= 0 ? pathInfo.Substring(0, slashIndex) : pathInfo;
     }
-}
\ No newline at end of file
+}