Levofloxacin is an antibacterial agent used for the treatment of many types of infections in adults. This is a randomized, open-label, parallel group, multicenter study to determine the safety and effectiveness of levofloxacin (500 mg by mouth once daily for 7-10 days) compared with another frequently used antibiotic, ciprofloxacin (500 mg by mouth every 12 hours for 7 -10 days), in adults with mild to moderate infections of the skin and the supportive layers beneath the skin. The study consists of 3 visits: one visit [pre-therapy] for screening and enrollment, and two visits to assess safety and effectiveness (one visit [on-therapy] on Days 3 - 5 of the study and one visit [post-therapy] 2 - 7 days after the last dose of the study drug). The total duration of patient participation in the study is approximately 2 weeks. The primary assessments of effectiveness include the clinical response to treatment (defined at post-therapy as cured, improved or failed) and the microbiological response at post-therapy (the rate of eradication of the disease-causing bacteria, determined by patient and by type of bacteria). Safety evaluations (incidence of adverse events, physical examination, physical examination of the skin, and laboratory tests) are performed throughout the study. The study hypothesis is that treatment with levofloxacin is at least as effective and as well tolerated as treatment with ciprofloxacin in patients with mild to moderate infections of the skin and the supportive layers beneath the skin. Levofloxacin 500 mg by mouth once daily, or ciprofloxacin 500 mg by mouth every 12 hours. The duration of treatment is 7 to 10 days.