How to upload images in drupal 6 form API?
Check the following article will help you easily go through:
Following are some drupal file form validate function
||Check that the filename ends with an allowed extension. This check is not enforced for the user #1.|
||If the file is an image verify that its dimensions are within the specified maximum and minimum dimensions. Non-image files will be ignored.|
||Check that the file is recognized byimage_get_info() as an image.|
||Check for files with names longer than we can store in the database.|
||Check that the file’s size is below certain limits. This check is not enforced for the user #1.|