I am getting this error when I do a delete.
If I take the "@" symbol off the userename it deletes the entire table. When I do this I get the message below.

ie DELETE FROM login WHERE (username = @username)
Must declare the scalar variable "@username".
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.SqlClient.SqlException: Must declare the scalar variable "@username".

Source Error:

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:


[SqlException (0x80131904): Must declare the scalar variable "@username".]
   System.Data.SqlClient.SqlConnection.OnError(SqlExc eption exception, Boolean breakConnection) +95
   System.Data.SqlClient.SqlInternalConnection.OnErro r(SqlException exception, Boolean breakConnection) +82
   System.Data.SqlClient.TdsParser.ThrowExceptionAndW arning(TdsParserStateObject stateObj) +346
   System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) +3244
   System.Data.SqlClient.SqlCommand.RunExecuteNonQuer yTds(String methodName, Boolean async) +272
   System.Data.SqlClient.SqlCommand.InternalExecuteNo nQuery(DbAsyncResult result, String methodName, Boolean sendToPipe) +367
   System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +149
   System.Web.UI.WebControls.SqlDataSourceView.Execut eDbCommand(DbCommand command, DataSourceOperation operation) +493
   System.Web.UI.WebControls.SqlDataSourceView.Execut eDelete(IDictionary keys, IDictionary oldValues) +918
   System.Web.UI.DataSourceView.Delete(IDictionary keys, IDictionary oldValues, DataSourceViewOperationCallback callback) +176
   System.Web.UI.WebControls.DetailsView.HandleDelete (String commandArg) +811
   System.Web.UI.WebControls.DetailsView.HandleEvent( EventArgs e, Boolean causesValidation, String validationGroup) +660
   System.Web.UI.WebControls.DetailsView.RaisePostBac kEvent(String eventArgument) +214
   System.Web.UI.WebControls.DetailsView.System.Web.U I.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +31
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEve ntHandler sourceControl, String eventArgument) +32
   System.Web.UI.Page.RaisePostBackEvent(NameValueCol lection postData) +244
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3840