The code below works fine, the problem is the 1st two lines are appearing on screen. It basically loads the PDF but I can't see the btnAcceptProposal change name or become enabled. Tried a Thread for the load but it broke. Anyone got any ideas - it's a web application

protected void btnPDFProposal_Click(object sender, EventArgs e)
{    
        btnAcceptProposal.Enabled = true;
        btnAcceptProposal.Text = "sss";

        byte[] p = Order.Proposal;
        Response.AppendHeader("content-disposition", "attachment; filename=Proposal.pdf");

        Response.ContentType = "Application/pdf";
        Response.Clear(); 

        Response.BinaryWrite(p);
        Response.End();
}