Question

I am working on a donations website. In my page, I have a textbox which accepts a numeric value from the user (that is, money to be donated).

In my code-behind, I have a method which checks whether the value in the textbox is numeric. The method generates an error message if the number is invalid.

I also have a JavaScript which, after checking that the value in the textbox is numeric, opens a new tab to the website confirmation page, thanking the user for his donation. Here is the code of the javascript:

<script type="text/javascript">
        function Open_Window()
        {
            var textbox = document.getElementById('DonationTextBox');

            if (textbox.value != "")
            {
                if (isNan(textbox) == false)
                {
                    window.open("DonationConfirmation.aspx")
                }
            }
        }
    </script>

The problem is that the tab is NEVER opened, even if the number is valid. Can you please help me solve this problem? Thank you.

P.S.

Here is the code of the button that initiates the validation:

<asp:ImageButton ID="PayPalButton2" runat="server" ImageAlign="Middle" 
                                        ImageUrl="Resources/Icons/PayPalCheckOut.gif" 
                                        onclick="PayPalButton2_Click" OnClientClick="Open_Window()"/>

Answer 1

<script type="text/javascript">
    function Open_Window()
    {
        var textbox = document.getElementById('<%=DonationTextBox.ClientID%>');                        
        if (textbox.value != "" && !isNaN(textbox.value)) {                
             window.open("DonationConfirmation.aspx");
        }
    }
</script>

edit


instead of isNan should be isNaN (javascript is casesensitive)