[phpMyAdmin Developers] longtext datatype request error

I have a website project to develop for my company. I actually think about using PHP/ MySQL for that purpose. One of my difficulties concern phpmyadmin and is the following : I need to save a record with a datatype < LONGTEXT > or < MEDIUM TEXT > (in fact the textarea must content until 2.000.000 caracters). When I test to register I obtain a pinky messagebox from mysql server saying that it is gone away... And no record has been done. So how can I use those two datatypes for longtext records ? And is there a configuration to define for the mysql server for such requests ? Thanks for your help. [cid:image001.jpg@01D3016B.88D2A130]