<FORM NAME="formu">
<TEXTAREA COLS="45" STYLE="width:99%;overflow:visible" name="content">contenu</TEXTAREA>
</FORM>

<script>

function addEvent(obj, evType, fn, useCapture) {
 if (obj.addEventListener) {
  obj.addEventListener(evType, fn, useCapture);
  return true;
 } else if (obj.attachEvent) {
  var r = obj.attachEvent("on" + evType, fn);
  return r;
 } else {
  alert("handler could not be attached");
 }
}

function addKeyEvent(obj,fnc_name) {
 var e = (document.addEventListener) ? 'keypress' : 'keydown';
 addEvent(obj,e,fnc_name,false);
}

function expand_tarea(tarea) {
 nb_line=escape(tarea.value).split("%0A").length+1;
 //nb_line=nb_line-1;
 if (nb_line<15) nb_line=15;
 tarea.rows=nb_line;
}

function manage_keys(e) {
 tarea = e.target || e.srcElement,

 // Get key code
 keyCode = e.keyCode || e.which;

 // Tabulation
 if (keyCode==9) {
  if (eval(document.selection)) {
   // For Internet Explorer
   document.selection.createRange().text = String.fromCharCode(9);
  } else {
   // For Mozilla/FireFox
   tbegin = tarea.value.substring( 0 , tarea.selectionStart );
   tend = tarea.value.substring( tarea.selectionEnd , tarea.textLength );
   tarea.value=tbegin.substring(0,tbegin.length)+'\t'+tend;
   tarea.setSelectionRange(tbegin.length+1,tbegin.length+1);
   e.preventDefault();
   e.stopPropagation();
 }
  e.returnValue=false;
 }
 // Adjust textarea
 expand_tarea(tarea);
}


expand_tarea(document.formu.content,0);
addKeyEvent(document.formu.content,manage_keys);
</script>