are these sentences correct? Is it all right to use "OK' in a sentence?<br/><br/>a) Would it be OK for me to work from 8 am to 3 p.m. next Tuesday as I have a dental appointment?<br/><br/>Or<br/><br/>b) Is it OK for me to work from 8 am to 3 pm. next Tuesday as I need to attend a dental appontment?