function ValidateActInsert() {

    var specialChars = /[^a-zA-Z0-9 ]/g;

    if (document.actorInsert.actInsert.value.match(specialChars)) {

        alert ("Only characters A-Z, a-z and 0-9 are allowed!")

        document.actorInsert.actInsert.focus();

        return false;

    }

    return (true);

}