[Zope] time.sleep() in dtml

Hello all, some python functions work in dtml, mostly mathematical ones. But what I do need at the moment is the "time.sleep(x)" function to prevent an immediate reply to a request of the users. I tried <dtml-var "_.time.sleep(1)"> and <dtml-var "_.sleep(1)">, but Zope returned an "Attribute error". Any ideas? Or do I have to create a special python method for this? (I'm not used to python until now...) Martin