Enter content in the first input box.textarea automatically gets the value of the first file box javascript code.

How to enter content in the first input.textarea automatically gets the value of the first file box;
That is to say, the first input is worthwhile when inputting textarea.
Thanks


<input   type=text   name="mytxt"   onkeyup="=">   
  <textarea   name='myTxta'>   
  </textarea>


<input   type="text"   onkeyup="send(this)">   
  <textarea   name="content"   cols=40   rows=5></textarea>   
  <script   language="javascript">   
  function   send(obj)   
  {   
  =   
  }   
  </script>


<input   type="text"   size="20"   onKeyUp="refreshValue(this)"></input>   
  <textarea      rows="4"   cols="40"></textarea>   
  <script   language="javascript">   
  function   refreshValue(obj)   {   
  var   s   =   ;   
  ("t1").value   =   s;   
  }   
  </script>