It is a very simple form as in the code below:
<form method="POST" action="news.php?nid=2">
<textarea id="txtcomment" style="width:100%; height: 70px;" maxlength="300"></textarea><br /><br />
<input type="submit" class="button" style="float: right; cursor:pointer;" value="Comment">
</form>
but in the news.php i cannot get the value of "txtcomment"
echo $_POST['txtcomment'];
it returns nothing...
It is because you need to name the textarea:
<textarea name="txtcomment"></textarea>
The id parameter does not have anything to do with how forms work (with the exception of labels, but that is not important here).
Specify the name attribute of the textarea.
Add name attribute in textarea
<textarea id="txtcomment" name="txtcomment" style="width:100%; height: 70px;" maxlength="300"></textarea>
you need to have an attribute name with txtcomment in it, you have an attribute 'id'
You have to define a name attribute (the id attribute is possible but not necessary).
<textarea name="txtcomment" ...>
textarea name must be txtcomment not id like
<form method="POST" action="news.php?nid=2">
<textarea id="txtcomment" name="txtcomment" style="width:100%; height: 70px;" maxlength="300"></textarea><br /><br />
<input type="submit" class="button" style="float: right; cursor:pointer;" value="Comment">
</form>
It's not id="" that names the field in your array, it's name="".
<textarea name="txtcomment" id="txtcomment" style="width:100%; height: 70px;" maxlength="300"></textarea><br /><br />
来源：https://stackoverflow.com/questions/16066731/cannot-get-the-value-of-a-textarea-via-post-method