The adequacy of overall model fit was estimated using chisquare test statistics and the following supplemental fit indices, root-mean-squared error of approximation (RMSEA), the comparative fit index (CFI) and Akaike's information criteria, AIC. In line with the conventional recommendations of Hu and Bentler [41] , a good model fit was indicated by a RMSEA less or equal to .06, a CFI greater or equal to .90 and with models having lower AIC being more plausible. The statistical significance of parameter estimates are the critical ratio (CR) representing the parameter estimate divided by its standard error. Based on a level of 0.05, the test statistics need to be <± 1.96 before the null hypothesis can be rejected. All other analyses were performed using SPSS 15.0 (SPSS, Inc, Chicago, Illinois, USA). Internal consistency reliability of-and bivariate associations among the theoretical constructs were assessed using Cronbach's alpha and Pearson's correlation coefficients, respectively. Unadjusted and adjusted marginal means and 95% confidence intervals for the components of the TPB and the construct of moral norm were estimated using General Linear Models, GLM (ANOVA). Linear multiple regression analysis was applied to predict intention from the TPB and external variables. The effect of the independent variables were expressed in terms of standardized regression coefficients (betas) and tested for statistical significance by means of F-test. The fit of the model was reported in terms of the squared multiple correlation coefficient (R 2 ).