Retuen none are available.

Example:

	println "The next available dbase file channel is ",DNEXT()

DNEXT was created in order to better support code libraries made possible by functions and procedures. File channel numbers can now be determined at runtime.
CAUTION! Until you actually OPEN a file DNEXT will return the same value over and over.
chan1 = DNEXT() chan2 = DNEXT() WRONG! chan1 will equal chan2
another gotcha: FOPEN DNEXT(),...
There is no way to determine what channel was used to open the file!
Here's an example of how it should be used:

	chan1 = DNEXT() FOPEN   chan1,...  
	chan2 = DNEXT() FOPEN   chan2,...  

See also: DBase functions