How to transfer parameters in a form in vb.net web application

Hi,
Do you know how to transfer parameters in a form in vb.net web application?
I can do it by defining a global variable in the module,but I want to define a variable with the scope is in one form not globally.I have tried defining a variable in the form like following:
'--------------------------------
Public Class ProductGroup
Inherits System.Web.UI.Page
Protected WithEvents ImageButton1 As System.Web.UI.WebControls.ImageButton
Protected WithEvents Label1 As System.Web.UI.WebControls.Label
Protected WithEvents ddForms As System.Web.UI.WebControls.DropDownList

public strTest as string
'-------------------------------------

But , after I set the value in one sub, I can't get the value of strTest in other sub.

Can you help me?

Thanks

wu7up

Hi,
I want to define module-class varibles in asp.net. These varibles can only be used when this web form is activate.
I have tried session.("strID") , but this session varible can be accessed in the next web form if the session doesn't die.
I also have tried defining a varible in aspx.vb file as well,just like defining form-class varibles in vb6. But every click will generate a new page and the value in the varible will be lost.

How can I define a varible which will die when it redirects to another webpage ,and, it will not lose value when the web page itself refreshs?


Thanks
wu7up