serious bug in editing the catalogue

Hi, I noticed something bad:
when you click on "Modify", change some fields like title or value that appear at the top of the page, and click on the save button before the whole page has loaded (it needs long time depending on the internet connection), it happens that all information in non-locked fields from the bottom of the page (edge description etc.) is deleted from the catalogue.
To the programmer: you should definitely check the fields whether they are set (php "isset()") before overwriting the values.

I hope the changes in the catalogue are saved and the Numista team can see which values have been deleted, like
user x changed field "edge description" from value "milled" to value ""
so the information can be restored