Just use resize: none
textarea {
resize: none;
}
You can also decide to resize your textareas only horizontal or vertical, this way:
textarea { resize: vertical; }
textarea { resize: horizontal; }
Finally,
resize: both enables the resize grabber.
<textarea style="resize:none" name="name" cols="num" rows="num"></textarea>
Just an example
example of textarea for disable the resize option
<textarea CLASS="foo"></textarea>
<style>
textarea.foo
{
resize:none;
}
</style>
Source: Stackoverflow.com