jquery - $('.block').height($(this).width()); causing block height extend -

i trying set block's height equal width $('.block').height($(this).width()); it's not working reason. please see example: http://jsfiddle.net/uy3yb/. need correct?

fiddle demo

$('.block').height(function () {     return $(this).width(); }); 

.height( function(index, height) )

a function returning height set. receives index position of element in set , old height arguments. within function, refers current element in set

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problem code

this below window object not $('.block')

$('.block').height($(this).width());