AxWebBrowser - targeting a frame.

[sde]

HTMLDocument document = (HTMLDocument)axWebBrowser1.Document;
HTMLInputElement ie = (HTMLInputElement)document.all.item("somefield",null);
ie.value = this.txtInput.Text;

that code will control "somefield" in the html document.

if the html document was in frames, how do i target "somefield" in one of the frames?