Method: EntryExists
Parameters
id
The ID of the entry to check
Description
This method lets you check whether or not an entry with a specific ID exists. Note that
GetEntry can also do this, but the SQL used might be slower and it requires additional lines to handle everything.
Return value
If an entry with the given ID exists, this method returns 1. If not, it returns 0.
If an error occurs, it sets the internal error flag and returns -1.