var r = /^((([a-z0-9_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,6}\;))*(([a-z0-9_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,6})))$/
var str = '[email protected];[email protected];[email protected]';
if (r.test(str))
var r = /^((([a-z0-9_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,6}\;))*(([a-z0-9_\.-]+)@([\da-z\.-]+)\.([a-z\.]{2,6})))$/
var str = '[email protected];[email protected];[email protected]';
if (r.test(str))