Editing Varchar field in Enterprise Manager

I am using SQL 2000. In a table (tblTestTable) I have a field VARHCAR(4000).
the field stores text taken from a text area in a web page so contains new line characters also length is around 2000 characters.

The problem is that I am unable to edit the text in this field through Enterprise Manager. The text remains as if it is readonly. All I can do is select entire text and cut or delete. :confused:
Is there reason for this occurance? How can it beovercome?Don't use EM?

It really wasn't made for that purpose, but I'll have a look.