problem in field object

[Gaurav Palvia]

hi pals,
   i am having problem in the field object.i have created a field
and using constructot i made its Single Line attribute false
and Dynamic Size attribute true,Max Chars to 100 but whaen i enter
in this field it does not expand and only the end chars are shown.
i want it to work in the same way as the name field in the address book
work.what should i do