directory_exists
This function checks whether a given directory exists.
bool directory_exists(string directory_name)
Parameters:
directory_name
The name of the directory to search for.
Return value:
true if the directory exists, false otherwise.
Remarks:
This function works with both absolute and relative paths.
Please note that the path may not end in a trailing slash or backslash, and may not contain wildcards.
Example:

    // Check if the Windows directory exists.

    void main()
    {
    if(directory_exists("C:\\windows"))
    {
    alert("Information", "Windows directory exists. I'd be slightly concerned if it didn't.");
    }
    else
    {
    alert("Oops", "You broke Windows! Hang on though, how on earth is it running?");
    }
    }