[Javascript] compose dynamical forms with JS

[javascript@xxxxxxxxxx (javascript@xxxxxxxxxx)]

Hello, suppose I have a page HTML:  
...  
< TD><SELECT SIZE="1 "NAME="appoint" onchange="creerText(this) "> 
<OPTION selected="">0</OPTION > 
<OPTION>1</OPTION>
<OPTION>2</OPTION > 
</SELECT></TD >...
I will wish that when the user selectionne a value (0,1 or 2) the 
function Javascript creerText() creates a zone of text (textarea) 
below the selection (<select>) in same page HTML.  
For example, I thought of following function JS:  
function creerText(obj) { 
 var zoneText = obj.selectedIndex; 
 for all zoneText do:  
 create a textArea;  
} 
But here, I do not manage to make so that my zones of text appear 
below the zone of selection.  Indeed, they appear in another page.  
This page HTML is a form which contains data that the utilsator filled 
progressively, so data must be saved when function JS is called.
In made, it is as if the utilsator built a "form dynamically".  
For example, the user could say, I would like 2 zones of text, 3 drop-
down menu of such size etc... and the page is built dynamically.  
Is it possible with HTML AND Javascript?  
Thank you,
Jean-Baptiste