its better you develop a mobile web page for mobile devices .
you can detect a mobile device using following code in the page load :
<pre lang="c#">
string strUserAgent = Request.UserAgent.ToString().ToLower();
if (strUserAgent != null)
{
if (Request.Browser.IsMobileDevice == true || strUserAgent.Contains("iphone") ||
strUserAgent.Contains("blackberry") || strUserAgent.Contains("mobile") ||
strUserAgent.Contains("windows ce") || strUserAgent.Contains("opera mini") ||
strUserAgent.Contains("palm"))
{
Response.Redirect("DefaultMobile.aspx");
}
}