Here is my problem

I have a form with 12 rows with all the same fields (row 1 has textbox1, checkbox1, etc.. Row 2 has textbox2, checkbox2, etc..)

If the form gets submitted I like to loop through the form data but how do I call the form data
for example checkbox+Z.Checked dos not work  in JS you can use eval() but that dos not work

For Z = 1 To 12

If checkbox+Z.Checked Then
                ‘Do something
End If

Next

you could try something like this:

    For Z As Integer = 1 To 12
      Dim controlName As String = "Checkbox" & Z.ToString
      Dim thisCheckbox As CheckBox = DirectCast(Page.FindControl(controlName), CheckBox)
      If Not thisCheckbox Is Nothing AndAlso thisCheckbox.Checked = True Then
        'Do something
      End If    
    Next

Hi Thanks but if do this i get a "Object reference not set to an instance of an object." Error
This is part of the script

For Z = 1 To 12
	Dim controlName As String = "ShowID" & Z.ToString
	Dim ShowID As DropDownList = DirectCast(Page.FindControl(controlName), DropDownList)

	controlName = "Onsale" & Z.ToString
	Dim Onsale As CheckBox = DirectCast(Page.FindControl(controlName), CheckBox)

	controlName = "PreStart" & Z.ToString
	Dim PreStart As BasicFrame.WebControls.BDPLite = DirectCast(Page.FindControl(controlName), BasicFrame.WebControls.BDPLite)

	controlName = "STime" & Z.ToString
	Dim STime As TextBox = DirectCast(Page.FindControl(controlName), TextBox)

	controlName = "PreEnd" & Z.ToString
	Dim PreEnd As BasicFrame.WebControls.BDPLite = DirectCast(Page.FindControl(controlName), BasicFrame.WebControls.BDPLite)

	controlName = "ETime" & Z.ToString
	Dim ETime As TextBox = DirectCast(Page.FindControl(controlName), TextBox)

	controlName = "Password" & Z.ToString
	Dim Password As TextBox = DirectCast(Page.FindControl(controlName), TextBox)

	controlName = "SDate" & Z.ToString
	Dim SDate As CheckBox = DirectCast(Page.FindControl(controlName), CheckBox)

	'test if field is empty
	If ShowID.Text.ToString <> "0" Then 'here i'm getting the "Object reference not set to an instance of an object." Error
		'Do something
	End If 
Next 

Check to see if ShowId is Nothing.

Findcontrol only finds controls inside the naming container from which findcontrol is called.

You could try replacing Page.FindControl with Me.FindControl if these controls are not directly on the page.

I tried it with Me.FindControl but i get the same error

I also tested ShowID1 to see if it is Nothing  but if i use ShowID1.Text i get the value so thats fine

I'm not sure why it is not working
 

Dim ShowID As DropDownList = DirectCast(Master.FindControl("Content").FindControl(controlName), DropDownList)

Yes - each placeholder declared on the masterpage represents a namingcontainer.

Findcontrol can only find controls declared within the naming container from which findcontrol is called.

So with a master page you get

Page 
   --- Master Page
       --- Master Page "Content" Placeholder 
           --- Your content

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