Block users from entering double-byte characters in textboxes [closed]
问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed last year . I want users to prevent entering double-byte characters in input fields. Following code will allow users to enter a-z or A-Z. I want users to prevent entering double-byte characters like Korean, Chinese etc. But users should be allowed to enter Spanish characters since those are not double-byte