Have you tried one of the outputs under Basic Tools ->Statistics ->Sum Data Bands?

Thanks mminari, that worked. What i wanted is  to normalize the image .I can create a sum^2 image from basic tools>statistics> sum^2 data bands. Now i want to divide every bands with sqrt(sum^2) image. Since sqrt(sum^2) band is a single band, dividing every bands with band math didnt work ! i think i have to replicate sqrt (sum^2)  image to match with no. of bands in my hyperspectral. Is there any way to do this in ENVI, with out plunging into IDL?? 

It seems like this should work in Band Math.  You can divide a multiband file by a single band.  The equation would be the same as b1/b2 where b1 would be mapped to the file containing the multiple bands and b2 would be the single band file.