function validateField(context) {
        var employee = context.currentRecord;
        
        if (context.fieldId == 'custentity_sdr_employee_code') {
            var empCode = employee.getValue('custentity_sdr_employee_code');
            
            if (empCode == 'x') {
                alert('Try Again');
                employee.setValue('custentity_sdr_employee_code', '');
                return false;
            }
        }
        return true;
    }