How to make divs equal height within a main container?

How to make divs equal height within a main container?

I am trying to make the divs within a main container have equal heights.I got this code from  http://stackoverflow.com/questions/11688250/setting-equal-heights-for-divs-with-jquery.

Here is a fiddle: http://jsfiddle.net/g9g869ny/

I am also trying to make it responsive(from max-width upto 768px), so If the device width scales down, I would like the script to recalculate the Height for every/any change in the WIDTH of the device - is it possible to constrain it that way?

Please help.