This jQuery plugin allow you to draw div on "click and drag"
Simply like this :
$(".drawSpace").dragAndDraw();
Some options can be added :
$(".drawSpace").dragAndDraw({
grid : [20,20],
top : 50,
left : 35,
width : 100,
height : 50,
start: function(container, createdDiv),
stop: function(container, createdDiv),
class: "some class names"
});