public class parameterCheck{
 public static bool isEmail(string emailString){
 return System.Text.RegularExpressions.Regex.IsMatch(emailString, "['//w_-]+(//.['//w_-]+)*@['//w_-]+(//.['//w_-]+)*//.[a-zA-Z]{2,4}");
 }
 public static bool isInt(string intString){
 return System.Text.RegularExpressions.Regex.IsMatch(intString ,"^(//d{5}-//d{4})|(//d{5})$");
 }
 public static bool isUSZip(string zipString){
 return System.Text.RegularExpressions.Regex.IsMatch(zipString ,"^-[0-9]+$|^[0-9]+$");
 }
}

 <appSettings>
 <add key="safeParameters" value="OrderID-int32,CustomerEmail-email,ShippingZipcode-USzip" />
</appSettings>

protected void Application_BeginRequest(Object sender, EventArgs e){
 String[] safeParameters = System.Configuration.ConfigurationSettings.AppSettings["safeParameters"].ToString().Split(',');
 for(int i= 0 ;i < safeParameters.Length; i++){
 String parameterName = safeParameters[i].Split('-')[0];
 String parameterType = safeParameters[i].Split('-')[1];
 isValidParameter(parameterName, parameterType);
 }
}

public void isValidParameter(string parameterName, string parameterType){
 string parameterValue = Request.QueryString[parameterName];
 if(parameterValue == null) return;

 if(parameterType.Equals("int32")){
 if(!parameterCheck.isInt(parameterValue)) Response.Redirect("parameterError.aspx");
 }
 else if (parameterType.Equals("double")){
 if(!parameterCheck.isDouble(parameterValue)) Response.Redirect("parameterError.aspx");
 }
 else if (parameterType.Equals("USzip")){
 if(!parameterCheck.isUSZip(parameterValue)) Response.Redirect("parameterError.aspx");
 }
 else if (parameterType.Equals("email")){
 if(!parameterCheck.isEmail(parameterValue)) Response.Redirect("parameterError.aspx");
 }
}