i need to build 2 html forms. the first one can be editable, and the second form will listen to first form which will enable it to have the same values for the variables. Here is the example of what i mean:

<script type="text/javascript">
function ChangeValue(NewValue)
document.getElementById("variable1").value = NewValue;

<form name="form1" method="post" action="/form1.php">
<input id="variable1" value="111">

<form name="form2" method="post" action="/form2.php">
<input id="variable2">

<button onclick="ChangeValue('333');">change value of 1st one</button>


in this example, i want the second input box to listen to the first one. when the first one changes, the second one should automatically dedect the change of the first one, and the second one should get the value of the first one.. (so in this example, when the "change value of 1st one" button is clicked, both of input boxes should get the value of 333)

how can we make it?
can anybody help me please, i really need this.
(i want to do this because i need to use 2 web forms which need to have the same variables with the same values but different action urls.)