这不是那么简单。时间表问题属于优化领域，其通常涉及多个约束和许多可能的解决方案。我建议你采用约束编程方法。阅读更多：

1. 学校时间表的约束编程方法 [ ^ ]

2. 以交互方式解决学校时间表问题

使用约束编程的扩展 [ ^ ]

AOA!
I am creating timetable. My question is that how do i create a how do i create a time slot for this .when one slot for the same teacher or class then we assign another slot and busy slot show a message that " slot is busy"

It is not that simple. Timetabling problems belong to the field of optimization which typically deals with multiple constraints and many possible solutions. I suggest you take the constraint programming approach. Read more:
1. Constraint programming approach for school timetabling[^]
2. Interactively solving school timetabling problems
using extensions of constraint programming[^]