[jQuery] File Exists

[jQuery] File Exists

<div dir="ltr">Hi all-
Looking for a way to determine if a file exists before uploading.  I'm working in <a href="http://asp.net">asp.net</a> and jquery, essentially my idea was to capture the submit of the form, and .get the file name to another page that would return true/false if the file existed.  If exists, confirm file overwrite, if not just post it. 
Problem is currently, it doesn't always catch that the file exists, and if I do get the confirm it seems to be ignored and just posts anyhow. 
Here's some of the code:
        <asp:FileUpload ID="FileUpload1" runat="server" />
        <asp:Button ID="Button1" runat="server" Text="Submit" />
   
        $(function(){
            $("#form1").submit(function() {
                return fileexists();
            });
        });
       
        function fileexists()
        {
            $.get("Exists.aspx", { file: $("#FileUpload1").val() }, function(data){
                if(data.toLowerCase() == "true")
                {
                    return confirm("Overwrite");
                }
                else
                {
                    return true;
                }
            });       
        }
Any help is appreciated,
Pete
</div>