Here is a question.
Every order has some receipt item and it has 1(order) to N(receipt item) relation with receipt item.
I wanna check that if there is any record  in receipt item of order entity or not.
How can it be possible?
I do like this happen in onload of the order and via JS, not workflow or something like that.
I wanna set  a button to Enable/Disable if there is any receipt item, so I need onload JS.
Is it possible? If yes how?
Any help or link? or sample?
Note that I have installed CRM 2011 on-permise.