Write Data Into Database From A Session?

I'm trying to write data from a session into database but it won't work.
Could someone help me what is wrong with this.

cobjDT = Session("cart")
For each cobjDR in cobjDT.rows
 Dim cmdInsert2 as New SQLCommand("order_details", loConn)
             cmdInsert2.CommandType = CommandType.StoredProcedure
            
cmdInsert2.Parameters.Add(New SqlParameter("@Orders", SqlDbType.int, 4,
"OrderID"))
            
cmdInsert2.Parameters("@Orders").Value = Request("OrderIDtext")
            
cmdInsert2.Parameters.Add(New SqlParameter("@PID", SqlDbType.int, 4,
"PID"))
            
cmdInsert2.Parameters("@PID").Value = Request(cobjDR("PID"))
            
cmdInsert2.Parameters.Add(New SqlParameter("@PakID", SqlDbType.int, 4,
"PakID"))
            
cmdInsert2.Parameters("@PakID").Value = Request(cobjDR("PAKID"))
            
cmdInsert2.Parameters.Add(New SqlParameter("@StyckPris",
SqlDbType.decimal, 9, "StyckPris"))
            
cmdInsert2.Parameters("@StyckPris").Value = Request(cobjDR("StyckPris"))
            
cmdInsert2.Parameters.Add(New SqlParameter("@Mangd", SqlDbType.int, 4,
"Mangd"))
            
cmdInsert2.Parameters("@Mangd").Value = Request(cobjDR("Quantity"))
             loConn.Open()
             cmdInsert2.ExecuteNonQuery()
             loConn.Close()
next            

When I execute this an error message comes


Server Error in '/examen' Application.

Input string was not in a correct format.



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.FormatException: Input string was not in a correct format.

Source Error:




Line 78: cmdInsert2.Parameters("@Mangd").Value = Request(cobjDR("Quantity"))Line 79: loConn.Open()Line 80: cmdInsert2.ExecuteNonQuery()Line 81: loConn.Close()Line 82: next







Source File: D:lofa.mine.nuexamenmembersTMP3thkwo1d0w.aspx    Line: 80


Stack Trace:




[FormatException: Input string was not in a correct format.] System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream) +723 System.Data.SqlClient.SqlCommand.ExecuteNonQuery() +194 ASP.TMP3thkwo1d0w_aspx.Page_Load(Object Sender, EventArgs E) in D:lofa.mine.nuexamenmembersTMP3thkwo1d0w.aspx:80 System.Web.UI.Control.OnLoad(EventArgs e) +67 System.Web.UI.Control.LoadRecursive() +35 System.Web.UI.Page.ProcessRequestMain() +731









Version Information: Microsoft .NET Framework Version:1.1.4322.573; ASP.NET Version:1.1.4322.573

I use same character types in storedProcedure what they are in the
database and when I call the SP on my page the char types are same as
they are in the SP

I don't see what the problem is. Please Help