Hi there, In fact, you are not dynamically adding the html input file control to the web page. What you are doing is to simply assign the ASP.NET markup (string) to the Text property of a Label control ( i guess so via the name lblMakeFileInput). So there is no input file control in the control hierarchy, so you cannot find it. If you want to dynamically create the control, you need to initialize the control with the new keyword as you would with a normal object, then add it to the Controls collection of a container like the Form, Panel, PlaceControlHolder ....Once you add it to the control hierarchy of the web page, you can find it using the FindControl method, Controls collection or you can keep the control variable that you create earlier.