Anytime you make a purchase on seetickets.us, an account is created in association with the email address entered at checkout.
Even if you checkout as a Guest, you can access your Order History by creating a password to access your account.
On the Sign In page, enter the email address you used to make the purchase and then click the "Forgot password?" link.
Be sure to check your Spam/Junk folder for the reset password email if you do not see it in your main Inbox.