Java EE (Java Enterprise Edition) General Discussion

hi
i need to display a text box when we select a particular radio button in a radio button group in a form
my code is :

<input Type="radio" name="group" value="B.tech">B.tech</input>
<input type="radio" name="group" value="M.tech" >M.tech</input>
<input Type="radio" name="group" value="Phd" >Phd </input>
<input Type="radio" name="group" value="Others"> Others</input>

these are my group of radio buttons

by default firt radio button will be checked

if the user Check last radio button "Others" then a "TEXT field" should be displayed

can any body help me out in these