Prueba con algo asi:
Código HTML:
<script language="javascript">
function sendForm(event){
var charCode = event.keyCode || event.which;
var element = event.srcElement || event.target;
if(charCode == 13) element.form.submit();
}
</script> ...
Código HTML:
<form onsubmit="retur false">
<textarea onkeypress="sendForm(event);"></textarea>
</form> Avisame si no funciona.
