I am writing a universal app for both iphone and ipad. How do I determine if the device is an iPad. I have used this link to determine the iPhone type (3G, 3GS).
Det
Brad's solution is absolutely right. If you're building a universal app designed to run on iPhones with older OS along with up-to-date iPads and iPhones, you might want to add this code to catch situations where the idiom is not defined.
// If iPhoneOS is 3.2 or greater then __IPHONE_3_2 will be defined
#ifndef __IPHONE_3_2    
typedef enum {
    UIUserInterfaceIdiomPhone,           // iPhone and iPod touch
    UIUserInterfaceIdiomPad,             // iPad
} UIUserInterfaceIdiom;
#define UI_USER_INTERFACE_IDIOM() UIUserInterfaceIdiomPhone
#endif // ifndef __IPHONE_3_2