How do I erase e-mails at once?

so i have a lot of e-mails that i just haven't read yet and i want to get rid of them, but how do u get rid of the e-mails you haven't read yet? i wanna be able to erase all of the e-mails i don't want to read all at once, but i can only seem to be able to erase them by checking them off and then erasing them after pager after page...help please...