<form id="ss">
<input type="text" name="title" value="welcome">
</form>
<script>
var qq="welcome to";
document.getElementById("title").value=qq;
</script>
<input type="text" name="title" value="welcome">
</form>
<script>
var qq="welcome to";
document.getElementById("title").value=qq;
</script>
<input type="text" name="title" value="welcome">
</form>
<script>
var qq="welcome to";
document.ss.all("title").value=qq;
</script>
<input type="text" name="title" value="welcome">
</form>
<script>
var qq="welcome to";
ss.title.value=qq;
</script>