Must declare the scalar variable "@YourName" ASP.Net C#

Im just having bad day with this error, my point is to get data from html tag and save it in database in sql server using C#.. i tried many articles in stackoverflow but didn't solve my problem.

here what i got: Must declare the scalar variable "@YourName"

also,Im trying to filter filter result in my database according to date, for example from specific date to specific date but it looks impossible :( .

Stack Trace:

[SqlException (0x80131904): Must declare the scalar variable "@YourName".] System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction) +2551578 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action1 wrapCloseInAction) +5951128 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose) +285 System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady) +4169 System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString, Boolean isInternal, Boolean forDescribeParameterEncryption, Boolean shouldCacheForAlwaysEncrypted) +255 System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite, Boolean inRetry, SqlDataReader ds, Boolean describeParameterEncryptionRequest) +2598 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource1 completion, Int32 timeout, Task& task, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) +1483 System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry) +374 System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +286 _Default.Save(Object sender, EventArgs e) in c:\Users\hussain.laith\Documents\Visual Studio 2017\WebSites\Linq\Home.aspx.cs:40 System.Web.UI.HtmlControls.HtmlButton.OnServerClick(EventArgs e) +116 System.Web.UI.HtmlControls.HtmlButton.RaisePostBackEvent(String eventArgument) +106 System.Web.UI.HtmlControls.HtmlButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +12 System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +15 System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +9884558 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1639

I would appreciate if you can help me guys.