On-flight cataloger SkyMall Inc., Phoenix, has trimmed its work force by 15%, or about 50 employees, with some of the cuts taken from its technology sectors. The company launched its new Web site and support infrastructure in February, and has eliminated positions it deems no longer essential. The layoffs came after the company, which had four profitable years prior to 1999, showed a net loss last year. The cataloger does not anticipate making any further staff reductions at this time. SkyMall uses airline seat pockets as its distribution mechanism.