how to upload an file on image button click

See more:

ASP.NET

I have an image button and i want to upload an file on cimage click.

my image button and uploader markup is

<asp:FileUpload ID="fplUploadExcel" runat="server" Style="position: relative; visibility: hidden;
                height: 20px;" ClientIDMode="Static" />

<asp:ImageButton ID="ImageButton1" runat="server" Width="150px" Style="position: relative;"
                ImageUrl="~/Images/Uploadingimage.jpg" />

And i m getting click of uploader as follws on page load is

ImageButton1.Attributes["onclick"] = string.Format("document.getElementById('{0}').click();", fplUploadExcel.ClientID);

but don't hoe to call the upload function please tell me how will i do this

my upload function is

protected void uploadExcel()
    {
        

        if (fplUploadExcel.HasFile)
        {
            // string excelfilepath = fplUploadExcel.PostedFile.FileName;
            //if (fplUploadExcel.PostedFile.FileName == "EmployeeSheet.xlsx")
            //{
            string filename = Server.MapPath(@"~\\Excel\\");
            fplUploadExcel.PostedFile.SaveAs(filename + fplUploadExcel.FileName);

            
            string excelfilepath = Server.MapPath("~\\Excel\\" + fplUploadExcel.FileName);

            importdatafromexcel(excelfilepath);

            SelectUpdaterecordFeromExcel();