Bootcamp problems

OK this does not happened to me it happens to a friend of mine so i need to know how to fix or how to avoid it before it happens to me : ok she intalled winxp using bootcamp on her Macbook. Now when she turn on her mac she must quickly press options for enter booting options menu, then choose to boot mac os X. If she turn on the Macbook without doing nothing Windows boots and starup automatically like if it were the primary operating system . now how can i solve this making Mac os X to boot automatically and for window by pressing option before mac os x boots??????????? can this be fixed at all or should i go with Parallels??

When she's in OS X, open the system preferences and click on Startup Disk. Then click on the OS X disk.