National Board Of Examination — correction of application

Sir,
I have successfully registered for aiq 50% but have not yet made any payment as i had selected "deemed" universities which i want to cancel before i make any payment.
M really tensed as m not getting any editing option.
Please help me with this.
I was to go back and change the fee criteria from "refundable fee"to "non refundable fee"
M tensed as even after qualifying for all india 50% quota i could lag behind just because there is no option to correct my application.
I haven't made any payment yet, i didn't go ahead of payment page.
I shall be thankful for helping me out as soon as possible.