Should i ignore her/?

well im trying to finish a two page essay that's due tomorrow well im logged in on msn but its set to away well one my friends ims me i tell her i cant talk busy and then she goes well your going to talk to me but i didn't reply for 5 minutes when i keep getting messages from her saying i know your there talk just basically abusing the im and ehile im writeing she still doing this i did make it look like i signed but even so shes still sending ims what to do?