i tried that code without radgrid and is working fine
<script type="text/javascript">
function sum() {
var txtFirstNumberValue = document.getElementById('txt1').value;
var txtSecondNumberValue = document.getElementById('txt2').value;
var result = parseInt(txtFirstNumberValue) + parseInt(txtSecondNumberValue);
if (!isNaN(result)) {
document.getElementById('txt3').value = result;
}
}
</script>
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If (Not Page.ClientScript.IsStartupScriptRegistered("test")) Then
Page.ClientScript.RegisterStartupScript(Me.GetType(), "test", "sum();", True)
End If
End Sub
But my problem was that i'm working with radgrid editform template, i have same 3 text boxes inside radgrid editform template, how to implement the above scenario with radgrid editform template