I am trying to set up my drop down boxes so that once someone selects their name from the employees (or authors) list and clicks a button called find my documents, it will populate the documents list. Here is my page code so far:
ublic Class WebForm7
Inherits System.Web.UI.Page

#Region " Web Form Designer Generated Code "

'This call is required by the Web Form Designer.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.SqlConnection2 = New System.Data.SqlClient.SqlConnection
Me.SqlDataAdapter2 = New System.Data.SqlClient.SqlDataAdapter
Me.SqlSelectCommand2 = New System.Data.SqlClient.SqlCommand
Me.SqlDataAdapter1 = New System.Data.SqlClient.SqlDataAdapter
Me.SqlSelectCommand1 = New System.Data.SqlClient.SqlCommand
'
'SqlConnection2
'
Me.SqlConnection2.ConnectionString = "workstation id=DAVIDSON8PC;packet size=4096;user id=intern;data source=ADMINSQL;p" & _
"ersist security info=True;initial catalog=Budget_Testing;password=tunvei4"
'
'SqlDataAdapter2
'
Me.SqlDataAdapter2.SelectCommand = Me.SqlSelectCommand2
Me.SqlDataAdapter2.TableMappings.AddRange(New System.Data.Common.DataTableMapping() {New System.Data.Common.DataTableMapping("Table", "dbo_List_employees", New System.Data.Common.DataColumnMapping() {New System.Data.Common.DataColumnMapping("EmployeeID", "EmployeeID"), New System.Data.Common.DataColumnMapping("EmpName", "EmpName")})})
'
'SqlSelectCommand2
'
Me.SqlSelectCommand2.CommandText = "dbo.[List_employees]"
Me.SqlSelectCommand2.CommandType = System.Data.CommandType.StoredProcedure
Me.SqlSelectCommand2.Connection = Me.SqlConnection2
Me.SqlSelectCommand2.Parameters.Add(New System.Data.SqlClient.SqlParameter("@RETURN_VALUE" , System.Data.SqlDbType.Int, 4, System.Data.ParameterDirection.ReturnValue, False, CType(0, Byte), CType(0, Byte), "", System.Data.DataRowVersion.Current, Nothing))
'
'SqlDataAdapter1
'
Me.SqlDataAdapter1.SelectCommand = Me.SqlSelectCommand1
Me.SqlDataAdapter1.TableMappings.AddRange(New System.Data.Common.DataTableMapping() {New System.Data.Common.DataTableMapping("Table", "dbo_list_Docs", New System.Data.Common.DataColumnMapping() {New System.Data.Common.DataColumnMapping("DocID", "DocID"), New System.Data.Common.DataColumnMapping("DocInfo", "DocInfo")})})
'
'SqlSelectCommand1
'
Me.SqlSelectCommand1.CommandText = "dbo.[list_Docs]"
Me.SqlSelectCommand1.CommandType = System.Data.CommandType.StoredProcedure
Me.SqlSelectCommand1.Connection = Me.SqlConnection2
Me.SqlSelectCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@EmployeeID", System.Data.SqlDbType.Int, 4, System.Data.ParameterDirection.ReturnValue, False, CType(0, Byte), CType(0, Byte), "", System.Data.DataRowVersion.Current, Nothing))
Me.SqlSelectCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@EmployeeID", System.Data.SqlDbType.Int, 4))

End Sub
Protected WithEvents Main As System.Web.UI.WebControls.Label
Protected WithEvents Warning As System.Web.UI.WebControls.Label
Protected WithEvents File_ver As System.Web.UI.WebControls.Label
Protected WithEvents File1 As System.Web.UI.HtmlControls.HtmlInputFile
Protected WithEvents Doc_List As System.Web.UI.WebControls.DropDownList
Protected WithEvents Document As System.Web.UI.WebControls.Label
Protected WithEvents Author_vers As System.Web.UI.WebControls.DropDownList
Protected WithEvents Author As System.Web.UI.WebControls.Label
Protected WithEvents Upload As System.Web.UI.WebControls.Button
Protected WithEvents SqlConnection2 As System.Data.SqlClient.SqlConnection
Protected WithEvents SqlDataAdapter2 As System.Data.SqlClient.SqlDataAdapter
Protected WithEvents SqlSelectCommand2 As System.Data.SqlClient.SqlCommand
Protected WithEvents Button1 As System.Web.UI.WebControls.Button
Protected WithEvents SqlDataAdapter1 As System.Data.SqlClient.SqlDataAdapter
Protected WithEvents SqlSelectCommand1 As System.Data.SqlClient.SqlCommand

'NOTE: The following placeholder declaration is required by the Web Form Designer.
'Do not delete or move it.
Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
'CODEGEN: This method call is required by the Web Form Designer
'Do not modify it using the code editor.
InitializeComponent()
End Sub

#End Region

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
Dim ds As New DataSet
SqlDataAdapter2.Fill(ds)
Author_vers.DataSource = ds
Author_vers.DataBind()




End Sub

Private Sub Author_vers_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Author_vers.SelectedIndexChanged
'Dim ds1 As New DataSet

'Me.SqlDataAdapter1.SelectCommand.Parameters.Add(" @EmployeeID", SqlDbType.Int, 4) '
''Dim param As SqlClient.SqlParameter = SqlSelectCommand1.Parameters.Item("@EmployeeID").V alue = Author_vers.SelectedValue
'SqlSelectCommand1.Parameters.Item("@EmployeeID"). Value = Author_vers.SelectedValue

'SqlDataAdapter1.Fill(ds1)
'Doc_List.DataSource = ds1
'Doc_List.DataBind()




End Sub

Private Sub SqlConnection2_InfoMessage(ByVal sender As System.Object, ByVal e As System.Data.SqlClient.SqlInfoMessageEventArgs) Handles SqlConnection2.InfoMessage

End Sub

Private Sub SqlDataAdapter2_RowUpdated(ByVal sender As System.Object, ByVal e As System.Data.SqlClient.SqlRowUpdatedEventArgs) Handles SqlDataAdapter2.RowUpdated

End Sub

Private Sub SqlDataAdapter1_RowUpdated(ByVal sender As System.Object, ByVal e As System.Data.SqlClient.SqlRowUpdatedEventArgs)

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim ds1 As New DataSet


'SqlSelectCommand1.Parameters.Add("@EmployeeID", SqlDbType.Int, 4)
''Dim param As SqlClient.SqlParameter = SqlSelectCommand1.Parameters.Item("@EmployeeID").V alue = Author_vers.SelectedValue
''SqlSelectCommand1.Parameters.Add("@EmployeeID", SqlDbType.Int, 4)
SqlSelectCommand1.Parameters.Item("@EmployeeID").V alue = Author_vers.SelectedValue
SqlDataAdapter1.Fill(ds1)
Doc_List.DataSource = ds1
Doc_List.DataBind()


End Sub

Private Sub Upload_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Upload.Click
'Dim create_Version As SqlClient.SqlCommand
'create_Version = New SqlClient.SqlCommand
'create_Version.CommandType = CommandType.StoredProcedure
'create_Version.CommandText = "create_Version"
'create_Version.Connection = SqlConnection2

'Dim emp_param As SqlClient.SqlParameter
'emp_param = New SqlClient.SqlParameter
'emp_param.ParameterName = "@EmployeeID"
'emp_param.SqlDbType = SqlDbType.Int
'create_Version.Parameters.Add(emp_param)

'Dim doc_param As SqlClient.SqlParameter
'doc_param = New SqlClient.SqlParameter
'doc_param.ParameterName = "@DocID"
'doc_param.SqlDbType = SqlDbType.VarChar
'create_Version.Parameters.Add(doc_param)
End Sub
End Class
My stored procedures are as follows:
CREATE PROCEDURE dbo.[list_employees] AS

select EmployeeID, LastName + ', ' + FirstName as EmpName
from Employee
GO

CREATE PROCEDURE dbo.[list_Docs]

@EmployeeID INT

AS
SET NOCOUNT ON


SELECT
Version.DocID,
[FileName] + '-' + CAST(ReviseDate AS VARCHAR) as DocInfo
FROM
dbo.Version, dbo.DocSys

WHERE
EmployeeID = @EmployeeID
AND
(
Version.DocID = DocSys.DocID --OR
--@EmployeeID = -1
)

ORDER BY
[FileName]
GO

Could someone please tell me why I get the error: Procedure 'list_Docs' expects parameter '@EmployeeID', which was not supplied.

I am doing this in Visual Basic with ASP.Net