i have a table look like this:

--------------
[0] |apple   |         (readonly)
---------------
[1] |           |
---------------

i can put [0].value to [1].value by entering the following script.
<script language="javascript">
document.all[txtField_1].value = document.all[txtField_0].value
</script>

However, the problem is i want to get the [0].readonly to [1] as well, i
failed to do that.
i've tried
if (document.all[txtField_0].readonly=true)
{
 document.all[txtField_1].readonly=true;
}
else
{
  document.all[txtField_1].readonly=false;
}

Please help