get input from file upload box to dll

[majestic0110]

Hi there, here is my class(that performs an XSLT)

public void Page_Load(Object sender, EventArgs E) {		
    string xmlPath = Server.MapPath("Help");
    string xslPath = Server.MapPath(blah blah); 
 
    XPathDocument doc = new XPathDocument(xmlPath);
		
    XslTransform trans= new XslTransform();
    trans.Load(xslPath);
		
    XmlTextWriter writer = new XmlTextWriter(Response.Output);
    writer.Formatting = Formatting.Indented;
    writer.Indentation=4;
    transform.Transform(doc, null, writer);
  }

So the listing is fine, does what we need BUT I need the Xml path to point at what a user inputs into a file upload button. I have no idea as to how I might approach this, have been doing some googling and it seems that I have a unique idea here lol. Thanks for your time!