Local js function to other site that will write a cookie

im the owner of domain A.com and B.com

in B.com i have handler (ashx) which writes a cookie.

now , im on A.com.

i want to call this handler from site A.com via Js(/jquery) that will activate the B.com's handler - and will write the cooki开发者_StackOverflow社区e of B.com in My browser.

does jsonP will help me here ?

i think you are looking for something like this

You already answered your own question, you can use jsonp for this. Some more info : http://api.jquery.com/jQuery.getJSON/