difference between this and element in ax 2012 where you can used in form level

any one reply me with example iam new into ax

this - current object

elemet - Form run object

you can find more information in below

http://stackoverflow.com/questions/4260403/this-vs-element-keyword-in-x

https://dynamicsaxinsight.wordpress.com/2014/05/08/ax-2012-this-vs-element-when-to-use-what/

This has been discussed several times in the forum. You can do a search.