Suppress Form Action

A custom server control has a Button.

Namespace Confirm
Public Class ShowConfirm : Inherits Button
Private strConfirmMsg As String
Public Property ConfirmMessage() As String
Get
ConfirmMessage = strConfirmMsg
End Get
Set(ByVal value As String)
strConfirmMsg = value
End Set
End Property

Protected Overrides Sub AddAttributesToRender(ByVal Output As HtmlTextWriter)
MyBase.AddAttributesToRender(Output)
Output.AddAttribute(HtmlTextWriterAttribute.OnClick, "ConfirmMsg()")
End Sub

Protected Overrides Sub RenderContents(ByVal Output As HtmlTextWriter)
Output.Write(vbCrLf)
Output.Write("<script language='JavaScript'>")
Output.Write(vbCrLf)
Output.Write("function ConfirmMsg(){")
Output.Write(vbCrLf)
Output.Write("var answer = confirm('")
Output.Write(strConfirmMsg)
Output.Write("')")
Output.Write(vbCrLf)

Output.Write("location.href = window.location.href + '?Proceed=' + answer")
Output.Write(vbCrLf)
Output.Write("}")
Output.Write(vbCrLf)
Output.Write("</script>")
End Sub
End Class
End Namespace

Using VBC, I compiled the above intoConfirm.dll. This is how I am using the above custom control in an ASPX page (assume that the ASPX page is namedConfirm.aspx):

<%@dotnet.itags.org. Register Assembly="Confirm" Namespace="Confirm" TagPrefix="CC" %
<form EnableViewState="true" runat="server">
<CC:ShowConfirm ID="ShowConfirm1" ConfirmMessage="WANNA EXIT?" Text="EXIT" runat="server"/>
</form>

Note the

Output.Write("location.href = window.location.href + '?Proceed=' + answer")

line (which is highlighted) in the VB class file code. When the ASPX page gets rendered, it displays a Button. Conventionally, when a Button is clicked in an ASPX page, it posts back to itself using the POST method. When the Button in the above custom control is clicked, a JavaScriptconfirm dialog pops-up with 2 buttons -OK &Cancel. IfOK is clicked, the value of the JavaScript variableanswer istrue & ifCancel is clicked, the value of the variableanswer isfalse.

What I want is irrespective of whether a user clicks theOK orCancel button in theconfirm dialog, instead of posting back to itself using the conventional POST method, I want the ASPX page to post to itself BUT with a querystringProceed=<value> appended i.e. I want to suppress the conventional post & instead add the querystring so that I can find out whether the user has clicked theOK button or theCancel button in theconfirm dialog. If the user clicksOK, he will be taken to

http://myserver/aspx/Confirm.aspx?Proceed=true

On the other hand, if the user clicksCancel in theconfirm dialog, he will be taken to

http://myserver/aspx/Confirm.aspx?Proceed=false

Can this be done in anyway?

Output.AddAttribute(HtmlTextWriterAttribute.OnClick, "ConfirmMsg();return false;")

Thanks, mate, your suggestion turned out to be a great one. Could you please tell me what role doesreturn=false; which you have appended afterConfirmMsg(), play here?

Going by your suggestion does add the querystringProceed=<value> at the end of the URL but there's a *** here. Suppose when a user clicks the server-side Button; he is shown the JavaScriptconfirm dialog with theOK &Cancel buttons. If the user clicksOK, then he is taken to

http://myserver/aspx/Confirm.aspx?Proceed=true

That's fine but if the user clicks the server-side Button once again & clicksCancel in theconfirm dialog, then he is taken to

http://myserver/aspx/Confirm.aspx?Proceed=true?Proceed=false

i.e. the querystring gets appended twice. In other words, a querystringProceed=<value> will go on getting appended at the URL wheneverOK &Cancel is clicked in the JavaScriptconfirm dialog. For e.g. if a user clicks eitherOK orCancel in theconfirm dialog 5 times, then the querystring will get appended one after the other 5 times.

Any workaround to overcome this?