Server Error in '/' Application.

Value cannot be null.
Parameter name: input

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentNullException: Value cannot be null.
Parameter name: input

Source Error: 


Line 21: 	sThisFile = replace(request.ServerVariables("URL"),"/","")
Line 22: 	Dim RegexObj as Regex = New Regex("[^A-Za-z0-9 ]")
Line 23: 	txtsearch = replace(RegexObj.Replace(Session("SearchStr"), ""),"  "," ")
Line 24: 	if trim(txtsearch) = "" or trim(txtsearch) = "Site Search" then
Line 25: 		txtsearch = "no search details entered"

Source File: E:\Hosting\aldeburgh-breaks.co.uk\golf_site_search.aspx    Line: 23

Stack Trace: 


[ArgumentNullException: Value cannot be null.
Parameter name: input]
   System.Text.RegularExpressions.Regex.Replace(String input, String replacement) +2145487
   ASP.golf_site_search_aspx.page_load(Object sender, EventArgs e) in E:\Hosting\aldeburgh-breaks.co.uk\golf_site_search.aspx:23
   System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15
   System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +33
   System.Web.UI.Control.OnLoad(EventArgs e) +99
   System.Web.UI.Control.LoadRecursive() +47
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1436

Version Information: Microsoft .NET Framework Version:2.0.50727.1433; ASP.NET Version:2.0.50727.1433