textarea中禁止换行

html

<textarea onkeydown="checkEnter(event)"></textarea>

javascript

function checkEnter(e) {  var et = e || window.event;  var keycode = et.charCode || et.keyCode;  if (keycode == 13) {    if (window.event) {      window.event.returnValue = false;    } else {      e.preventDefault(); //for firefox    }  }}