display image in grid based on condition

Hi, in my application,
i want to display some data in gridview.there is an image column in gridview.
i want to add an image in that column after checking the particular id is in a folder.
ie a folder named pdf and that contains 2.pdf,3.pdf . i have 5 records with id 1,2,3,4,5.
in 2 an 3 i want to display an image. rest of records that that column should be blank.
how it is possible.

Regards
Baiju
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