Untitled

Onclick firing twice in Chrome, not IE or Firefox
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="test.aspx.vb" Inherits="test" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
<script type="text/javascript" language="javascript">

    function GenerateNewNumber() {
        var randomnumber = Math.floor(Math.random() * 1234);
        document.getElementById('NumberLabel').innerHTML += '<br>' + 'Random Number is ' + randomnumber;
    }

</script>
</head>
<body>
    <form id="form1" runat="server">

    <asp:LinkButton ID="Button1" runat="server" OnClientClick="GenerateNewNumber(); return false;">Click for Random Number Test 1</asp:LinkButton><br />
    <a id="Button2" href="#" onclick="GenerateNewNumber(); return false;" target="_blank">Click for Random Number Test 2</a>
    <asp:Label ID="NumberLabel" runat="server"></asp:Label>
    </form>
</body>
</html>

protected override void OnPreInit(EventArgs e)
{
    if (Request.UserAgent != null && (Request.UserAgent.IndexOf("AppleWebKit") > 0))  // added for compatibility issues with chrome
    {
         this.ClientTarget = "uplevel";
    }

     base.OnPreInit(e);
}