creating a multiline textbox and validating it

Hi,

I am new to forum for NAV. Hope get solution soon.

I want to add a text box(Multiline) which will accept the product detail from the user. the first line will be "product no" which will not be greater then 18 chars and then its description, etc, etc which will not be greater then 32 chars per line.

The problem, am facing is,

1)Cant create a textbox which can accept multiple lines 2) if multiline is possible how to do the above validation.

Please help.