after determination can I work?urgent help, please answer

[guvener]

I received a letter from Tribunal Services confirming that my appeal about my Student Visa was successful and a determination outlining the reasons for this was sent to me on 18.05.2010.
I was advised to contact UK Border agency if after six weeks from the date of decision I have not received any correspondence. I contacted UKBA by phone and they didnt help me. 12 weeks from the date of decision passed and I am still waiting some kind of correspondence from UK Border Agency. I am going to a work interview next week and I just have the letter from Tribunal saying that my visa was allowed. I do not have yet my Immigration Identify Card and I know that it will take ages to come... I just have the letter to prove that I can continue in the country. do you think I can be accepted to work?
Can an employer offer me a contract in this condition?wt should I do?