Hola,como estamos todos'How do you say in Spanish:
"If you're not in Ibiza for August,you don't know what you're missing and probably never will!"
Thankyou very much for your help Mark W,full credit will be given to you should anybody ask and royalties will be paid if anyone else wants to use it!
Si no estás en Ibiza en agosto, no sabes lo que estás perdiendo, y seguramente nunca lo sabrás.
Si usted no se encuentra en Ibiza el mes de agosto, usted deja pasar la oportunidad de divertirse.
If you are not in Ibiza in August, you will miss the opportunity of enjoying yourself.
I would wait for more answers, as a native speaker may be able to give you exactly what you require.
Thankyou for that but how would you say it generally to anyone,I want to use it for the introduction on my MSN messenger.
I can only translate what you have written "literally". I choose not to do this as it would probably harm a Spaniards ears. So this is my take on it with a variation.
Si no te encuentras en Ibiza el mes de agosto, tu dejas pasar la oportunidad de divertirte.
This is of course, talking to someone with whom you are familiar.