// Begin isValid // Checks validity of email form contents function isValid(form) { var text = ""; var missing = false; if (form.firstname.value == "") { text = text + "First Name. "; missing = true; } if (form.lastname.value == "") { text = text + "Last Name. "; missing = true; } if (form.email.value.indexOf("@") == "-1" | form.email.value.indexOf(".") == "-1" | form.email.value == "") { text = text + "Email. "; missing = true; } if (missing == true) { alert("The following fields are missing and/or invalid: " + text); return false; } else { return true; } } // End isValid