iam getting the following error. i dont have any clue on how to solve it.

below is my web.config for profile settings

<providers>

<properties>

<add name="LastName" type="String" allowAnonymous="true" />

<add name="BirthDate" type="DateTime" allowAnonymous="true" />

<add name="Website" type="String" allowAnonymous="true" />

<add name="Posts" type="Int32" allowAnonymous="true" />

<add name="Signature" type="String" allowAnonymous="true" />

<add name="Street" type="String" allowAnonymous="true" />

<add name="City" type="String" allowAnonymous="true" />

<add name="Country" type="String" allowAnonymous="true" />

<group name="Contacts">

<add name="Fax" type="String" allowAnonymous="true" />

</profile>

i dont know why iam getting the error

System.Configuration.SettingsPropertyNotFoundException was unhandled by user code
  Message="The settings property 'FirstName' was not found."
  Source="System"
  StackTrace:
       at System.Configuration.SettingsBase.GetPropertyValueByName(String propertyName)
       at System.Configuration.SettingsBase.get_Item(String propertyName)
       at System.Web.Profile.ProfileBase.GetInternal(String propertyName)
       at System.Web.Profile.ProfileBase.get_Item(String propertyName)
       at System.Web.Profile.ProfileBase.GetPropertyValue(String propertyName)
       at ProfileCommon.get_FirstName() in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\onlinedairy\cda5190c\ff69aa9e\App_Code.ndhjwpnt.7.cs:line 156
       at UserControls_userprofile.Page_Load(Object sender, EventArgs e) in e:\asp.net\OnlineDairy\UserControls\userprofile.ascx.cs:line 60
       at System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e)
       at System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e)
       at System.Web.UI.Control.OnLoad(EventArgs e)
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Control.LoadRecursive()
       at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

check your database you might have written FirstName in different way.