<html><head></head><body>
<form name="form1" method="post" action="">
</form>
<p>
<input type="text" name="textfield" size="20">
</p>
<p>
<input type="button" name="Submit" value="Submit" onclick="textfield.style.visibility='hidden';document.write('<input type=button>')">
</p>
</form>
</div>
</body></html>
<form name="form1" method="post" action="">
</form>
<p>
<input type="text" name="textfield" size="20">
</p>
<p>
<input type="button" name="Submit" value="Submit" onclick="textfield.style.visibility='hidden';document.write('<input type=button>')">
</p>
</form>
</div>
</body></html>
<p>
<input type="text" name="textfield" style='display:inline' size="20">
<input type="text" name="textfield2" size="20" style='display:none'>
</p>
<p>
<input type="button" name="Submit" value="Submit" onclick="textfield.style.display='none';textfield2.style.display='inline';">
</p>
</form>