Can't open log in page

My 17 inch Macbook Pro battery died about 6 months ago. I finally got a replacement battery and fixed it. Everything was working fine until I did the software updates which required a restart. It starts up fine but when I get the account log in page nothing happens. I can't click on my account name to enter the password.I cant even click on sleep,restart or shutdown It doesnt respond. The battery is full - it just wont let me in. Any suggestions ?

Welcome to Mac-Forums..

What version of OS X is this?

Can you get into safe mode to see if things work?

Mac OS X: Starting up in Safe Mode

Also try clearing the NVRAM/PRAM

About NVRAM and PRAM

Thanks for getting back to me so quickly...I dont know why but it suddenly kicked in. The trackpad may be working differently, I dont know. But anyway, Im in. I'll be back if anything else goes wrong! Thanks