Hi Jon,

I believe postbackURL lets the button post to a different page. I am
assuming you want to redirect the user in some way? Instead, set the button's
commandargument property to the URL you want, and then at the end of the
OnClick event, redirect the user to the value of the CommandArgument Property.

You can refer to the code below for this:

protected void LinkButton1_clk(object sender, EventArgs e)
       {
           if (someVariable == 2)
           {
               Response.Redirect(LinkButton1.CommandArgument.ToString());
           }
       }

Hope this helps.

Regards,
Manish