Can any one tell me what is this film name which is almost 10-15 years old?

Story goes like this: a scientist invented a machine which makes human beings very smaller in size. Machine was placed in a room and No one was allowed to go inside. Children when playing cricket in the lawn, the ball hits the window glass, goes insite the room where the machine is and presses the keys of the machine. 3/4 children and 1 adult goes inside to trace the ball, rays fall on all of them and become very smaller......... And the story is the problems they face until they regain their original size. They become so small that they all ride on an ant.

I was trying at many of the Film Stores but no one could help me. I thank you all in advance to help me Please.