Implicit conversion from data type varchar to varbinary(max) is not allowed. Use the CONVERT function to run this query.

if (uploadresume.HasFile == true)
{
if ((uploadresume.PostedFile.ContentLength / 1024) <= 300)
{
cn.Open();
Stream fs = uploadresume.PostedFile.InputStream;
BinaryReader br = new BinaryReader(fs);
Byte[] bytes = br.ReadBytes((Int32)fs.Length);
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "pupusrresume";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.AddWithValue("@loginemailid", Convert.ToInt32(Session["loginemailid"].ToString()));
//cmd.Parameters.AddWithValue("@resume", usrresume);
cmd.Parameters.Add("@resume", SqlDbType.VarBinary).Value = bytes;
cmd.Connection = cn;
cmd.ExecuteNonQuery();
cn.Close();
//clear();
Page.ClientScript.RegisterStartupScript(this.GetType(), "Updated", "<script>alert('Yor resume Updated')</script>");
}
}