copy one NSString to another

How to copy one NSString to another?

@interface MyData : NSObject
{
    @private

    //user's private info
    NSInteger uID;
    NSString *name;
    NSString *surname;
    NSString *email;
    NSString *telephone;

    //user's picture
    UIImage *image;
}

@property (nonatomic, assign) int uID;
@property (nonatomic, retain) NSString *name;
@property (nonatomic, retain) NSString *surname;
@property (nonatomic, retain) NSString *email;
@property (nonatomic, retain) NSString *telephone;
@property (nonatomic, retain) UIImage *image;
@end

I have two objects of this type. MyData *obj1, obj2;

First is initialized. Second I want to initialize with first.

obj2 = [obj1 copy];   //crashes

    newData.surname = data.surname;   //crashes to
    newData.email = data.email;
    newData.telephone = data.telephone;

I neeeeed a COPY of second object NOT RETAIN!!! Help please! Thanx!

your object should probably implement the copy itself:

@implementation MyData

-(id)copyWithZone:(NSZone *)zone
{
    MyData *obj = [[[self class] alloc] init];
    obj.uID = self.uId;
    obj.name = self.name
    ...
    return obj;
}

....
@end