Isolation of code in SPL

Hello, I have written a procedure that needs to create a temp table. ... do something select ... into temp tablename ... do something drop table tablename... The table is dropped when I finish to use it. The problem is that the procedure can be executed by several users at the same time and the table is the same for all. So the table can't be created while another user is using it, and haven't dropped it yet. Can isolate this parts of code with set isolation or set transaction? I think these statements work to isolate access to table rows, but I need to isolate code (and so the entire temp table). Anybody can explain to me a solution? I am using Online Dynamic Server 7.2 Thanks