用 stepwise logistic regression with several categorical predictors. I kept getting error message: "factor variables not allowed"

Why do I get this error message? How to fix it?


Here is my code (dv=dependent variable)：

stepwise, pr(.1) lockterm1: logistic dv ib3.v1 i.v2

总是得到这个错误信息：
"factor variables and time-series operators not allowed"

问题在哪？怎么改？