Half Marathon Login?

I reacently signed up for my first half marathon and unfortunatly I have forgoten my login details, as the half marathon website does not have a "forgot pass" or "forgot username" I can't find a way to log in! Is there a way to get my details back or is it not acctually necessary to log in again after you have applied?

There should be a 'contact us' link on most websites ... which 1/2m was it that you entered?
You wouldnt usually need to go back unless you had details to change I suspect

Thanks for your help, I have since contacted the site via email. I have entered the Sheffield Half.