javascript - Passing value from one field to another -

i want pass value 9112232453 of 1 textfield another.

i know need javascript don't know how it.

html

<form method = "post" action="">   <input type="checkbox" name="phone" value="9112232453" onclick='some_func();' >   <input type="text" name="phone" value="" id="phone">   <input type="submit" name="go"> </form>  

then later, want use value in php.

you use js. function take param (this.value) like:

<script>         var some_func = function  (val){             var input = document.getelementbyid("phone");             input.value = val;         } </script>  <form method = "post" action="">     <input type="checkbox" name="phone" value="9112232453" onclick='some_func(this.value);' >     <input type="text" name="phone" value="" id="phone"> <input type="submit" name="go">     </form>