Add operation doesn't work with Chrome, Firefox

[seratch]

It works on Safari. Maybe code should be refactored.

[tkawachi]

It seems that <form> can't be placed immediately inside of <tr>. Chrome interpret it as an empty <form>.
http://stackoverflow.com/q/1824673/339515

One solution might be to wrap a whole table with the <form> tag.

[seratch]

Thanks. I'll fix this when I have time.