abnormal margin in my facebook iframe application

the size of my application isnt the full 760 pixels, i am getting about 750.

i based my application on this template: http://thinkdiff.net/facebook/graph-api-iframe-base-facebook开发者_运维百科-application-development/

iframe size is set to resizable.

The problem was there was a default margin on the i had to set the margin and padding to 0.