'Change value of a textbox, compared to another text box value with a ratio

I am working on ASP.NET C#.

With Javascript, I need to change the value of a textbox, when another text box value changes with the ratio of 3:2.

For example, if the value in a text is 150, the other textbox value should be 100.

javascriptc++sharpasp.net


Solution 1:[1]

Try this,

Javascript:

<script type="text/javascript">
    function fill() {
        document.getElementsByName('txt2')[0].value) = (document.getElementsByName('txt1')[0].value) * (2 / 3);
    }
</script>

Code in body tag:

<form id="form1" runat="server">
<div>    
    <%--The text boxes must have numeric values--%>
    <asp:TextBox ID="txt1" runat="server" onchange="javascript:fill();"></asp:TextBox>

    <asp:TextBox ID="txt2" runat="server"></asp:TextBox>
</div>

Hope this helps.

Solution 2:[2]

use something like this

<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
function change() {    
    var t1Val = (document.getElementById("t1")).value;
    (document.getElementById("t2")).value = ((t1Val * 2) / 3);
};
</script>
</head>
<body>

<input id="t1" type="text" onchange="change()"/>
<input id="t2" type="text"/>

</body>
</html>

If is there any validation you need you can write inside change() function.

http://jsfiddle.net/bdd63/1/

Solution 3:[3]

You may use onchange or onkeyup events on the text box

Add the following java-script function to your html

function ChangeValue() {
    if (document.getElementById('txtval1').value) {
        document.getElementById('txtval2').value=document.getElementById('txtval1').value*2/3;
    }
}

then add two text-boxes with ids txtval1,txtval2 to your html, add onkeyup="ChangeValue(); to the first one

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1
Solution 2
Solution 3 GDP

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