hide drop down field when specific email (@abc.com or @xyz.com) is inputted

I'm building a registration form and I need to h开发者_如何学编程ide a drop down field when a specific email is inputted. So when a user with email id of john*@abc.com* is added the drop will disappear. I hope this makes sense. Thanks.

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$("#email").keyup(function(){
    $("#dropdown").toggle($(this).val() != "john*@abc.com");    
});

http://jsfiddle.net/hunter/hnRxm/