While working on some 'animation' effect on one of my pages, I came across a problem when using setTimeout() . I am using it to call a function repeatedly in certain interval. I am not much into javascript so had quite a trouble figuring it out. If the function which is being called does not have any input parameters, setTimeout(MyFunc(),10); // calls 'MyFunc' function every 10 ms. But my 'Animate' function takes a parameter ( divId ),so I tried setTimeout(Animate(divId),10); // wrong !! This did not work. The correct way to call a function with parameters in setTimeout function is. setTimeout( function (){Animate(divId);}, 10); This concept is called 'Closure' in javascript. Just wanted to share...