Create this form. Pulling the corner of which, you can stretch and compress the field horizontally and vertically.
HTML
<form>
<textarea rows="2" cols="50" OnKeyUp="ResizeTextArea(this,2);"></textarea>
</form>
We set the minimum dimensions and embellish.
textarea {
width: 30em;
height: 5em;
border-radius: 3px;
box-shadow: 0 1px 5px rgba(0, 0, 0, 0.7);
}
Javascript
function countLines(strtocount, cols) {
var hard_lines = 1;
var last = 0;
while ( true ) {
last = strtocount.indexOf("\n", last+1);
hard_lines ++;
if ( last == -1 ) break;
}
var soft_lines = Math.ceil(strtocount.length / (cols-1));
var hard = eval("hard_lines " + unescape("%3e") + "soft_lines;");
if ( hard ) soft_lines = hard_lines;
return soft_lines;
}
function ResizeTextArea(the_form,min_rows) {
the_form.rows = Math.max(min_rows,countLines(the_form.value,the_form.cols) +1);
}
That's all. Such a small but very useful script.