Simplebrowser - Click a button on a web page

Question

Good morning,

I am trying to upload a file online and upload this uploaded file after clicking the button. All this using Simplebrowser. However, in no way I can click this button, I believe that something of the site itself is preventing the click. I do not know how to solve. I need some hint. Follow a part of the code.

1) Save the file in the required location 2) Click to Send (but do not load)

       browser.Find("input", FindBy.Name, "field(-manter-arquivo)").Value = sArquivo;
       browser.Find("form", FindBy.Id, "enviarpliForm").SubmitForm();