The field doesn't adjust proportionately according to the height & width we have set.

Thanks much for your kind assisntance.
It does helps alot where resizing is concern.
However, the field doesnt adjusted proportionately according to the height
& width we have set, ie: 300 (H) x 250 (W) pixels.
Would appreciate if you could assist me on this?

You can adjust the height and width of the fields by using the form designer. Here's how:

1. Go to Form Designer

2. Click on the textbox to open Textbox styles

3. Edit the "textbox height" to change the field height

4. Edit the "textbox and textarea width" to change the field width

For more info on the form designer, you can check out this guide: Form Designer Tutorial: Let's create fantastic forms!
Regards.