slideDown function: The . slideDown () method animates the height of the matched elements. This causes lower parts of the page to slide down, appearing to conceal the items.can be supplied to indicate durations of 200 and 600 milliseconds, Demo link : http://freeteachnology.hol.es/slidedown/ Code link : https://drive.google.com/open?id=0BxmTZPVcu72fSUxycV9FT1hDZjg Syntax : $(element).slideDown (speed,easing,callback); follwoing parameterr of slideUp element : 1-spedd, 2-easing, 3-callback, 1-speed : specifies speed of slide down effects, speed used milesecond,slow,fast parameter pass 2-easing :specify speed of slideDown element 1-swing-move slower at the begining/end but faster at middle, 2-linear – constant speed. 3-callback : slide down function excuted call callback function. Follwoing file structure create : 1-header.php, 2-footer.php, 3-index.php 1-header.php file include bootstrap links well as jquery link, Code :...