parameterCheck.cs 

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]

+$");

    }

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");

    }