How to Check Images File Exist? in different server

Hi,

I have 10 different coldfusion server.

for example 9 server is for the web application site - for example http://myserverone/studentweb

the other one is for images website, just for displaying student picture - for example http://myserverimage/studentpicture.
the purpose of this website is to display student picture that i store as gif files.


from my studentweb website i will call the images from studentpicture website as source for my image placeholder.
for example this is my code i'm calling form http://myserverone/studentweb website:

<img src=" http://myserverimage/studentpicture/#studentnumber#.gif" alt="" name="studentpicture" width="160" height="200">

my problem is, if there is no specific student picture in my studentpicture website, then the placeholder will display an X ( mean the images not found )

how do i prevent the X to display?
how do i using coldfusion or any kind of way to check if the images exist on that website ( different server ), so if the images is not found, i can display a default images? i can do this if i'm calling the website in the same server, but not using a different server.

this is like using other website images for your own personal website and sometimes the owner delete the images from their website, and i want to display my own images if that images been removed from the source website.

anyone have done this before?

thanks for suggestion and guide...

haire