How to apply dwt2() as the function of block processing

I have image with size 256*256.I want to sub divide this image into 4*4 blocks with overlapping by using

B = blkproc(A,[4 4],[2 2],fun) function.Now i want to apply 

[cA1,cH1,cV1,cD1]=dwt2(B,'haar') 

for each block.(I want to apply one level wavelet transformation to blkproc function).How to apply dwt2 into blkproc fun  .thanks! if you can plz help me immediately .

[mahesh chathuranga]

please help me.i'm in trouble.