How to update 2 textboxes with javascript ?

[rider_1]

Mates,

How can I update a multiple textboxes value with javascript, when user change the value of textboxes, and I have a value already on those textboxes ?

<input type="text" id="amount_textbox" onChange="UpdateValue()" value="100">
<input type="text" id="amount_textbox" onChange="UpdateValue()" value="200">

function UpdateValue()
    {
    //alert ("you have changed the textbox...");
    var x = document.getElementById('amount_textbox').value;
    document.getElementById("amount_textbox").setAttribute("value", x);
    document.getElementById('amount_textbox').value = x;

   }

    }

That function is working only for the first textbox, but how can I make other textbox worked ?

Thanks

[daveVk]

<input type="text" id="amount1_textbox" onChange="UpdateValue(this)" value="100">
<input type="text" id="amount2_textbox" onChange="UpdateValue(this)" value="200">

function UpdateValue(el)
{
//alert ("you have changed the textbox...");
var x = el.value;
el.value = x; // should this be the other textbox ?
}

You should not use the same id on multiple elements.

Passing (this) into function simplifies matters, the ids are no longer needed for this bit of code at least.

setting attribute value redundent ?

[rider_1]

it didn't work fine, I've tried at
[jsfiddle.net...]

[daveVk]

try [jsfiddle.net...]