Information Disappears On Button Click?

I have a ListView that has a FileUpload control and a button in each ListViewItem. I have an OnClick event on my button where i try and pull information from the FileUpload control, but when I try to access the control all of the values that were set are gone (FileName etc).

What do I need to do differently here to access the information I just entered?

<asp:ListView ID="lv_Uploads" runat="server" OnItemDataBound="GetThumbs" EnableViewState="true" >
<LayoutTemplate>
<div id="itemPlaceholder" runat="server" />
</LayoutTemplate>
<ItemTemplate>
<div style="width:500px;>.......

Code behind:

protected void SaveFile(object sender, EventArgs e)
{
//This always evaluates to an empty string...
string myFile = ((FileUpload)((Button)sender).Parent.FindControl("fu_Upload")).FileName;
}