Try this:
function Confirm() {
var confirm_value = document.createElement("INPUT");
confirm_value.type = "hidden";
confirm_value.name = "confirm_value";
if (confirm("Your asking")) {
confirm_value.value = "Yes";
document.forms[0].appendChild(confirm_value);
}
else {
confirm_value.value = "No";
document.forms[0].appendChild(confirm_value);
}
}
In Button call function:
<asp:Button ID="btnReprocessar" runat="server" Text="Reprocessar" Height="20px" OnClick="btnReprocessar_Click" OnClientClick="Confirm()"/>
In class .cs call method:
protected void btnReprocessar_Click(object sender, EventArgs e)
{
string confirmValue = Request.Form["confirm_value"];
if (confirmValue == "Yes")
{
}
}