Self-assessment tax: form fill-up

hi,

 I am paying self assessment tax and filling up the form. I have a doubt. there are many fields(e.g. income tax, interest, education cess, penality) in the form. I think we are supposed to divide the self-assessment tax we are paying among these fields. my question is that is it mandatory to divide the amount or can I give the whole amount in a single field?

One more doubt, I need to pay some 234A/C interest, should I write that amount in interest field.

My case is that I have around 300 rs. income tax remaing and some 1500 rs. interest.

please guide.