Image forming apparatus and control program

A non-transitory recording medium storing a computer readable control program that is executed by a computer that controls an image forming apparatus including:

• a plurality of paper feed trays that feed accommodated sheets of paper;
• a detector that detects absence of paper in the paper feed trays;
• and an image former that forms an image on a sheet of paper fed from one of the paper feed trays based on a print job issued, the computer readable control program causing the computer to perform:
• (a) detecting, by the detector, absence of paper in the paper feed tray in use during execution of the print job;
• (b) identifying a job attribute of the print job issued;
• (c) selecting a first tray switching condition or a second tray switching condition that is more lenient than the first tray switching condition in accordance with the job attribute identified;
• and
• (d) switching to another paper feed tray that satisfies the tray switching condition selected.