var format = /[ `!@#$%^&*()_+-=[]{};':"|,.<>/?~]/;
// ^ ^
document.write(format.test("My@string-with(some%text)") + "<br/>"); //true
document.write(format.test("My string with spaces") + "<br/>"); //true
document.write(format.test("MyStringContainingNoSpecialChars")); //false