i have a problem with access database in visual web developer

hello , i have a problem with access database in visual web developer , when i want to or insert a record to my access database it shows me this error messege :
thanks for your help.


Server Error in '/kurdpedia' Application.


You tried to assign the Null value to a variable that is not a Variant data type. 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.Data.OleDb.OleDbException: You tried to assign the Null value to a variable that is not a Variant data type.

Source Error:

Code:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

Code:

[OleDbException (0x80004005): You tried to assign the Null value to a variable that is not a Variant data type.]
   System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(OleDbHResult hr) +65
   System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult) +181
   System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult) +307
   System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult) +77
   System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method) +188
   System.Data.OleDb.OleDbCommand.ExecuteNonQuery() +112
   System.Web.UI.WebControls.SqlDataSourceView.ExecuteDbCommand(DbCommand command, DataSourceOperation operation) +493
   System.Web.UI.WebControls.SqlDataSourceView.ExecuteInsert(IDictionary values) +549
   System.Web.UI.DataSourceView.Insert(IDictionary values, DataSourceViewOperationCallback callback) +173
   System.Web.UI.WebControls.FormView.HandleInsert(String commandArg, Boolean causesValidation) +623
   System.Web.UI.WebControls.FormView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup) +745
   System.Web.UI.WebControls.FormView.OnBubbleEvent(Object source, EventArgs e) +163
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +56
   System.Web.UI.WebControls.FormViewRow.OnBubbleEvent(Object source, EventArgs e) +118
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +56
   System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e) +106
   System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument) +177
   System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +31
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +32
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +242
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3837

Version Information:Microsoft .NET Framework Version:2.0.50727.42; ASP.NET Version:2.0.50727.42 <!--
[OleDbException]: You tried to assign the Null value to a variable that is not a Variant data type.
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(OleDbHResult hr)
at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult)
at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method)
at System.Data.OleDb.OleDbCommand.ExecuteNonQuery()
at System.Web.UI.WebControls.SqlDataSourceView.ExecuteDbCommand(DbCommand command, DataSourceOperation operation)
at System.Web.UI.WebControls.SqlDataSourceView.ExecuteInsert(IDictionary values)
at System.Web.UI.DataSourceView.Insert(IDictionary values, DataSourceViewOperationCallback callback)
at System.Web.UI.WebControls.FormView.HandleInsert(String commandArg, Boolean causesValidation)
at System.Web.UI.WebControls.FormView.HandleEvent(EventArgs e, Boolean causesValidation, String validationGroup)
at System.Web.UI.WebControls.FormView.OnBubbleEvent(Object source, EventArgs e)
at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
at System.Web.UI.WebControls.FormViewRow.OnBubbleEvent(Object source, EventArgs e)
at System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args)
at System.Web.UI.WebControls.LinkButton.OnCommand(CommandEventArgs e)
at System.Web.UI.WebControls.LinkButton.RaisePostBackEvent(String eventArgument)
at System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)
at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
[HttpUnhandledException]: Exception of type 'System.Web.HttpUnhandledException' was thrown.
at System.Web.UI.Page.HandleError(Exception e)
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest()
at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context)
at System.Web.UI.Page.ProcessRequest(HttpContext context)
at ASP.admin_kurdish_history_aspx.ProcessRequest(HttpContext context)
at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
-->