window.onload = function () { var t = document.getElementsByTagName('textarea')[0]; var offset = !window.opera ? (t.offsetHeight - t.clientHeight) : (t.offsetHeight + parseInt(window.getComputedStyle(t, null).getPropertyValue('border-top-width'))); /** * The following three code clocks are for proper resizing of the input textarea */ var resize = function (t) { t.style.height = 'auto'; t.style.height = (t.scrollHeight + offset ) + 'px'; } t.addEventListener && t.addEventListener('input', function (event) { resize(t); }); t['attachEvent'] && t.attachEvent('onkeyup', function () { resize(t); }); }