lost input box code

Hi
I have a series of input boxes under the AutoOpen command so when the file is opened a serious of questions are asked and the user has to enter data into the input boxes that are then recorded in differing places in the opening workbook.

Eg, Sub AutoOpen ()
x = InputBox ("what is you name?")......

Problem is, I want to make some amendments but I do not semm to be able to locate the code in VB Editor???
I open the file in Excel, then click 'view code' and nothing?? This is probably very simple, but it is frustrating as I cant find it. Other code, such as command button code is there, but nothing for the AutoOpen Input boxes???????
Hope someone can help.