As you mentioned, change its easy but it occurs big problems in the standard working. I recommend to you to make a New field, with your extended length (for example Description 3) and put this to the form. Make a code of this field OnValidate event to fill the original Description until length of the Description field, truncate the extended text value. Of course it is okay if you would like to only register a higher capacity of field, but it is not going through your standard processes. Take care of this and plan the all of your process, where could be occurs any malfunction.