Sometimes it takes more than 8 minutes for someone to even noticed you have posted -- it's not like there's someone sitting here 24/7 waiting to hop on a newly created thread and answer... patience!
To erase (I'm assuming you mean "erase," not "delete") your hard drive, boot from the Mac OS X Install CD/DVD, then select "Disk Utility" from the "Installer" or "Utilities" menu. Select your hard drive on the list at the left, then click "Erase."