set texture of a sprite is not working - objective-c

Question

i am trying to set texture with this :
[[self setSpriteByTag] setTexture:[[CCTextureCache sharedTextureCache] addImage:[NSString stringWithFormat:#"%#0001.png",face]]];
when [self setSpriteByTag] return a sprite face is an image string, and they both ok because i have logged them.
this sprite is a child of a page in ccscrolayer :
one page of the layer pages :
CCLayer *page1 = [[CCLayer alloc] init];
BACK.position=ccp(screenSize.width/2,screenSize.height/2);
[page1 addChild:BACK];
when i was trying to change BACK's image , with the command i wrote here.
what happen is that i see a white screen.
i have check that the image is in my assets .
what could be the problem ?
the facr that i change a sprite that is a child of a page ?
edit :
this is the function that gives me the sprite BACK:
-(CCSprite*)setSpriteByTag
{
int currentPage=[scroller currentScreen];
[globals sharedGlobals].currentPageG=currentPage; //move to touch ended?
currentPage=currentPage+1;
//NSLog(#"PAGE:%d",currentPage);
if(currentPage==1)
{[globals sharedGlobals].WhatFace =#"BeastFace"; return BACK;}
else if(currentPage==2)
{[globals sharedGlobals].WhatFace =#"BlueFace"; return BACK1;}
else if(currentPage==3)

Answer 1

It gets white only in case when image is not present in the resources.. I checked running same code.. It works fine.. If I put wrong name of the image which is not present.. It changes to white... Please check for the image
[NSString stringWithFormat:#"%#0001.png",face]
M sure problem is in the image name.. :)

Answer 2

[NSString stringWithFormat:#"%#0001.png",face]
Your filenames will have to have the format "xxxxx0001.png". Assuming the face variable is the string "BeastFace" then the filename to load will be "BeastFace0001.png".
So far the obvious but keep in mind that the file "Beastface0001.png" will not load on the device, and neither will "beastface0001.png" because iOS devices use a case-sensitive file system. It will work on the iOS Simulator though.