For two-arm randomized control (RCT) pilot study (AIM 3), 100 current smokers will be observed to examine the preliminary effect of bidirectional SMS smoking cessation intervention. Subjects will be randomized into two groups (intervention vs. control), and compare the carbon monoxide (CO) validated 7-day point prevalence smoking abstinence rates at 4-week follow-up between intervention group (SMS smoking cessation treatment) and control group (assessment texts only).