regarding lock objects

hi gurus,

i have developed a module pool in which i gave one push buttton called save...

under this button i coded some logic,,,,,during the execution of this logic i want that no body can access my customized database table zmseg (for eg)....so how can i lock my database table during the execution of this logic ...sud i use lock objects concept if yes plz let me know about the coding....step by step...

thnx in advance....

plz help me.