Transaction Handling Problem

Hi all i am using Vs 2005 for Web application Development.

At one place i have to update 2 tables and i have to insert in 1 table.For that i am using following function.

But i am getting error pls help me.

My function is.

Public Function UpdateItemDetails(ByVal executemode As ExecuteMode, ByVal Remarks As String, ByVal userid As String, ByVal ItemDetails As ArrayList, ByVal rfsno As String, ByVal rfsstatus As String) As Integer

Try

Dim sql As String

Dim con As New SqlConnection(conString)

con.Open()

cmd.Connection = con

trans = con.BeginTransaction()

cmd.Transaction = trans

''Updating TSMS_RFSITEMDETAILS Table.For Each acc As item1 In ItemDetails

Dim Itemid As String = acc.INameDim quantity As String = acc.QUANTITY

Dim Total As String = acc.TOTAL

sql = "update " + tabPrefix + "RFSITEMDETAILS set QUANTITY=@QUANTITY,TOTAL=@TOTAL,REMARKS=@REMARKS where ITEM_ID=@ITEM_ID"cmd.Parameters.Add("QUANTITY", SqlDbType.NVarChar, 50).Value = acc.QUANTITY

cmd.Parameters.Add("TOTAL", SqlDbType.NVarChar, 255).Value = acc.TOTALcmd.Parameters.Add("ITEM_ID", SqlDbType.Int, 10).Value = acc.INamecmd.Parameters.Add("REMARKS", SqlDbType.NVarChar, 50).Value = Remarks

cmd.CommandType = CommandType.Text

cmd.CommandText = sql

cmd.ExecuteNonQuery()Next

''Updating TSMS_RFS Table.

sql = "update " + tabPrefix + "RFS SET RFS_STATUS=@RFS_STATUS,UPDATEDBY=@UPDATEDBY where RFS_NO=@RFS_NO"

cmd.Connection = concmd.Parameters.Add("RFS_STATUS", SqlDbType.Int, 50).Value = rfsstatus

cmd.Parameters.Add("RFS_NO", SqlDbType.NVarChar, 10).Value = rfsnocmd.Parameters.Add("UPDATEDBY", SqlDbType.Int, 50).Value = userid

cmd.CommandType = CommandType.Text

cmd.CommandText = sql

cmd.ExecuteNonQuery()

''Inserting TSMS_ORDER_STATUS_HISTORY Table.

cmd.CommandText = "insert into " + tabPrefix + "ORDER_STATUS_HISTORY(RFS_NO,ORDER_STATUS_ID,UPDATEDBY)values(@RFS_NO1,@ORDER_STATUS_ID,@UPDATEDBY1)"cmd.Parameters.Add("RFS_NO1", SqlDbType.NVarChar, 50).Value = rfsno

cmd.Parameters.Add("ORDER_STATUS_ID", SqlDbType.Int, 50).Value = rfsstatuscmd.Parameters.Add("UPDATEDBY1", SqlDbType.Int, 50).Value = userid

cmd.ExecuteNonQuery()

trans.Commit()Catch ex As Exception

_LastError = ex

trans.Rollback()

Finally

con.Close()

End Try

End Function

 

I am getting following error Second time in For loop when control reached to

cmd.ExecuteNonQuery(). This Statement.

Error is:  The variable name '@QUANTITY' has already been declared. Variable names must be unique within a query batch or stored procedure.

Please Help me.