upload: better validation

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>
upload improvement

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>
upload update

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>
upload update

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>
upload update

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>
upload update

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>
upload update

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>
minor errors

Signed-off-by: A. van der Pluijm <info@urbanlink.nl>