Implementing tabular data Management with JavaScript

Use JavaScript to achieve the following functions of tabular data management:

• · Click the Add button to add an empty record that can be modified.
• · Click the table cell to modify the text.
• · The saved interface is implemented after modification.
• · If you add a new record without making any modification values NULL, the Save all will be ignored.
• · Save all of the modified values, the original data will not be repeatedly saved.
• · Prompts to save if the data is not saved while refreshing.
• · Click Delete if the invalid data is temporarily added to delete directly, if the record is saved to achieve the record deletion of the interface.