View image or pdf failure. How to redirect a page without avoiding server error ?

[eluser]quest13[/eluser]
I have a grid on which 'View' button is shown. On clicking, it will open a pdf file to a new page. I used a anchor_popup function to do this. But If there is no such file exists or error in a file path, how do I avoid showing "server error" ? I tried to give a condition in which the view path if failed will take to 404_error.php, but that didn't seem to work.

Can anyone tell me is there any default method in CI to do this ?

Thanks in advance.