How to disable form submit button if text field value is set to a specific value or blank?

如何禁用形式如果文本字段的值设置为特定值或空白的提交按钮？

youdao

How to disable form submit button if text field value is set to a specific value or blank?

如何禁用形式如果文本字段的值设置为特定值或空白的提交按钮？

youdao