iphone - Nsstring data isnt retianed after passing a controller -

my nsstring data being lost when transfer view controller 1 view controller 2 viewcontroller 3. when transfer viewcontroller 1 viewcontroller 3 works. way switching viewcontroller 1 view controller 2 causing me lose nsstring data reason. post code below, guess need in view controller 2.

viewcontroller1

-(void)button{     stringentered=textfield.text;     viewcontroller2 *vc2 = [[viewcontroller3 alloc] init];     vc2.string = [[nsstring stringwithstring:textfield.text] retain];      [self.navigationcontroller pushviewcontroller:vc2 animated:yes];  } 

viewcontroller 2

-(void)button{     viewcontroller3 *vc3 = [[viewcontroller3 alloc] init];     [self.navigationcontroller pushviewcontroller:vc3 animated:yes]; } 

viewcontroller3

nsstring *emailbody = [nsstring stringwithformat:@"%@",string]; 

in viewcontroller 3 .h file write below line

@property(retain,nonatomic)nsstring *string; 

and synthesize in .m file

@synthesize string; 

now in viewcontroller 2

-(void)button{     viewcontroller3 *vc3 = [[viewcontroller3 alloc] init]; vc3.string =string;     [self.navigationcontroller pushviewcontroller:vc3 animated:yes]; } 

make sure have define string in vc2 properly.