if you mean the foreach loop with excel example in chapter five, here is what i did to make the example work.
on page 139, when you create the <new variable> "ExtractFileName", make sure you assign a value to the variable (i.e c:\folder\filename.xls).
also, on page 140, connectionstring is wrong. you should select excelfilepath and assign it to your variable. click evaluate expression and you'll see the value you assigned to on page 139.