I have a string as a HTML source and I want to check whether the HTML source which is string contains a tag which is not opened.

For example the string below contains `</u>` after WAVEFORM which has no opening `<u>`.

```
WAVEFORM</u> YES, <u>NEGATIVE AUSCULTATION OF EPIGASTRUM</u> YES,

```

I just want to check for these types of unopened tag and then I have to append the open tag to the start of the string?