Question

so how do set the left and top..(even when i scroll the scrollBar)

thanks

Answer 1

machine elf and Stefan Kendall are both very close but both incomplete so you just combine each as so (machine elf didn’t account for scrollbars and Setfan didn’t account for the height and width of the div itself):

Assuming your id for your div is “myDiv”

$('#myDiv').css('position','fixed');
$('#myDiv').css("left", ($(window).width()/2-$('#myDiv').width()/2) + "px");
$('#myDiv').css("top", ($(window).height()/2-$('#myDiv').height()/2) + "px"));

You may also need to set the css of your div to a fix height and width and its display is set to “block”. You can do this with JQuery as well.

Also, you can combine all these into one long string.