email_capture_anywhere.js

function validateEmail(email) {
    var re = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(email);
}

emailCaptured = false;

(function($) {
	
	$("input[type='text']").on('keyup', function (e) {
	    email = $(this).val();
		if ( validateEmail(email) && emailCaptured == false ) {
			setTimeout(function(){
				emailCaptured = true;
				alert("POST... " + email);
			}, 2000);
		}
	});

})( jQuery );