I have one Mysql table field that is not updating on my PHP website.

I have a small issue. One of my fields on my php website is not updating when i use admin panel or myphpadmin. Before this issue i was able to update this field anytime i wanted. For example if the data for that field is $0.00
and i update it to $20 it still shows $0.00. I need this fixed in 30 mins.