I am devoloping the bubble shooter game in cocos2d how to generate random bubbles from array of sprites here is my code

(void)addTarget {

CGSize winSize = [[CCDirector sharedDirector] winSize];


//CCSprite *target = [CCSprite spriteWithFile:@"3.png" rect:CGRectMake(0, 0, 256, 256)]; 

NSMutableArray * movableSprites  = [[NSMutableArray alloc] init];
NSArray *images = [NSArray arrayWithObjects:@"1.png", @"2.png", @"3.png", @"4.png",@"5.png",@"1.png",@"5.png", @"3.png",  nil];       
for(int i = 0; i < images.count; ++i) {


    NSString *image = [images objectAtIndex:i];

    // generate random number based on size of array (array size is larger than 10)



    CCSprite*target = [CCSprite spriteWithFile:image];
    float offsetFraction = ((float)(i+1))/(images.count+1);
    target.position = ccp(winSize.width*offsetFraction, winSize.height/2);
    target.position = ccp(350*offsetFraction, 460);

    [self addChild:target];
    [movableSprites addObject:target];






    //[target runAction:];
    id actionMove = [CCMoveTo actionWithDuration:10 position:ccp(winSize.width/2,winSize. height/2)]; 

This code generating bubbles with *.png colour bubbles but i want to generate randomly because for shooting the bubbles by shooter class help me please

    id actionMoveDone = [CCCallFuncN actionWithTarget:self selector:@selector(spriteMoveFinished:)];
    [target runAction:[CCSequence actions:actionMove, actionMoveDone, nil]];






}       

}