how can i locate an image link source

At the bottom of my zencart an image shows which is default image of 'no_picture' but how can i remove that image link from my website as i could'nt found its source any idea ?

If you right click on the image and select properties you will see the location of that image, which you can then replace or delete. This is useful in case you don't have a photo for a product yet though.

Also in admin go to configuration->images and in there you can turn off image required.

hth

I have mentioned in my post that it is sowing default image 'no_picture' in bottom of my page but how can i remove that link which enforce this image to my page either it is some module or whatever thanks

Davidinho gave you the answer - in your admin go to Configuration > Images > Product Image - No Image Status and change it to "0". You can also set Image Required to "false".