How do I assign the value of a label to a variable?

I have code for the onclick event of a button on the form and I want to redirect to another page passing the value of a label as a sesion variable. I cant figure out how to set the value of the label to a variable so I can assign it to the session. Here is what I've tried.

Session("WorkOrderID") = Me.Controls(0).FindControl("lblWorkOrderID").ToString

Response.Redirect("AddWorkOrderDetail.aspx")

 

What am I doing wrong? Thanks for any help
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