Line 32: You're comparing an uninitialized variable.
Line 19: What's the purpose of the int customers array inside tab?
Line 28: This should be tab.
Line 37: You call currentCustomerCount, but currentCustomerCount is uninitialized (garbage).
Line 44: total is undefined.
Line 59-81: Lots of problems here. tab t is local and goes out of scope when enterAtab exits.
currentCustomerCount needs to be passed by reference.
Line 74: You need to assign t to customers[currentCustomerCount] and increment currentCustomerCount.
Lines 75-79: These values were never set.
PLEASE USE CODE TAGS (the <> formatting button) when posting code.
It makes it easier to read your code and also easier to respond to your post.
http://www.cplusplus.com/articles/jEywvCM9/
Hint: You can edit your post, highlight your code and press the <> formatting button.