global.asax to enable CORS on IIS server

cors.global.asax

<%@ Application Language="C#" %>

<script runat="server">
	void Application_BeginRequest(object sender, EventArgs e)
	{
		var context = HttpContext.Current;
		var response = context.Response;
		
		// enable CORS
		response.AddHeader("Access-Control-Allow-Origin", "*");
		response.AddHeader("X-Frame-Options", "ALLOW-FROM *");
		
		if (context.Request.HttpMethod == "OPTIONS")
		{
			response.AddHeader("Access-Control-Allow-Methods", "GET, POST");
			response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept");
			response.AddHeader("Access-Control-Max-Age", "1728000");
			response.End();
		}
	}
</script>