[DotNetDevelopment] File Upload to mqsql database problem

[nag]

hii dear all,
im getting following error while uploading file to mysql database

Object reference not set to an instance of an object

here is my code please anyone help me to do the same

  <table align ="center" class="panel1" style="width: 99%; height:
118px;">
            <tr>
                <td style="width: 464px; height: 21px; text-align:
left;">
                    Description: &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp;<asp:TextBox ID="txtFileName" runat="server"></
asp:TextBox></td>
            </tr>
            <tr>

            </tr>
            <tr>
                <td style="width: 464px; text-align: left;">
                    Document: &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;
&nbsp; &nbsp;<input id="File1" runat="server" type="file"
style="width: 266px" /></td>
            </tr>
            <tr>
                <td style="width: 464px; height: 26px;">
                    <asp:Button ID="Button1" runat="server"
Text="Upload" OnClick="Button1_Click" /></td>
            </tr>

        </table>


C# code

String strConnectionString = "Driver={MySQL ODBC 3.51
Driver};Server=mysql8.brinkster.com;Database=dv;user
id=dv;password=bv";

    protected void Button1_Click(object sender, EventArgs e)
    {
        FileInfo imageInfo = new FileInfo(File1.Value.Trim());
        //if (!imageInfo.Exists)
        //    this.RegisterClientScriptBlock("alertLabel1",
"<script>alert('please select one image file.');</script>");
        //else
        //{
            switch (imageInfo.Extension.ToUpper())
            {
                case ".JPG": this.UpLoadImageFile(imageInfo); break;
                case ".GIF": this.UpLoadImageFile(imageInfo); break;
                case ".BMP": this.UpLoadImageFile(imageInfo); break;
                case ".ZIP": this.UpLoadImageFile(imageInfo); break;
                case ".DOC": this.UpLoadImageFile(imageInfo); break;
                case ".PDF": this.UpLoadImageFile(imageInfo); break;
                case ".wmv": this.UpLoadImageFile(imageInfo); break;
                default: this.RegisterClientScriptBlock("alertLabel1",
"<script>alert('file type error.');</script>"); break;
            }
        //}
    }
    private void UpLoadImageFile(FileInfo info)
    {
        OdbcConnection objConn = null;
        OdbcCommand objCom = null;
        try
        {
            byte[] content = new byte[info.Length];
            FileStream imagestream = info.OpenRead();
            imagestream.Read(content, 0, content.Length);
            imagestream.Close();
            objConn = new OdbcConnection(strConnectionString);
            objCom = new OdbcCommand("insert into dg_admainfile
(Description,Filename,Picture,Type,cid,pid)values(?,?,?,?,?,?)",
objConn);
            OdbcParameter categorynameParameter = new OdbcParameter
("@Description", OdbcType.NVarChar);
            if (this.txtFileName.Text.Trim().Equals(""))
                categorynameParameter.Value = "Default";
            else
                objCom.Parameters.Add("@Filename",
OdbcType.NVarChar).Value = System.IO.Path.GetFileName
(File1.PostedFile.FileName);
            objCom.Parameters.Add("@Type", OdbcType.NVarChar).Value =
System.IO.Path.GetFileName(File1.PostedFile.ContentType);
            objCom.Parameters.Add("@cid", OdbcType.Int).Value = Session
["clientid"].ToString();
            objCom.Parameters.Add("@pid", OdbcType.Int).Value = Session
["projectid"].ToString();
            categorynameParameter.Value = this.txtFileName.Text.Trim
();
            objCom.Parameters.Add(categorynameParameter);

            OdbcParameter pictureParameter = new OdbcParameter
("@Picture", OdbcType.Image);
            pictureParameter.Value = content;
            objCom.Parameters.Add(pictureParameter);
            objConn.Open();
            objCom.ExecuteNonQuery();
            objConn.Close();
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }
        finally
        {
            objConn.Close();
        }
    }


table name : dg_clientfile

Description --VARCHAR(45)

Filename--VARCHAR(45)
Picture --LONGBLOB
Type ---VARCHAR(45)

cid --INTEGER

pid --INTEGER